| <?xml version="1.0"?> |
| <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"> |
| <refentry id="re-drbdsetup"> |
| <refentryinfo> |
| <date>5 Dec 2008</date> |
| <productname>DRBD</productname> |
| <productnumber>8.3.2</productnumber> |
| </refentryinfo> |
| <refmeta> |
| <refentrytitle>drbdsetup</refentrytitle> |
| <manvolnum>8</manvolnum> |
| <refmiscinfo class="manual">System Administration</refmiscinfo> |
| </refmeta> |
| <refnamediv> |
| <refname>drbdsetup</refname> |
| <refpurpose>Setup tool for DRBD |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| </indexterm> |
| </refpurpose> |
| </refnamediv> |
| <refsynopsisdiv> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">disk</arg> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>lower_dev</replaceable> |
| </arg> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>meta_data_dev</replaceable> |
| </arg> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>meta_data_index</replaceable> |
| </arg> |
| <arg choice="opt" rep="norepeat">-d<arg choice="req" rep="norepeat"><replaceable>size</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-e<arg choice="req" rep="norepeat"><replaceable>err_handler</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-f<arg choice="req" rep="norepeat"><replaceable>fencing_policy</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-b</arg> |
| <arg choice="opt" rep="norepeat">-t<arg choice="req" rep="norepeat"><replaceable>disk_timeout</replaceable></arg></arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">net</arg> |
| <arg choice="opt" rep="norepeat"> |
| <replaceable>af:</replaceable> |
| </arg> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>local_addr</replaceable> |
| </arg> |
| <arg choice="opt" rep="norepeat"> |
| <replaceable>:port</replaceable> |
| </arg> |
| <arg choice="opt" rep="norepeat"> |
| <replaceable>af:</replaceable> |
| </arg> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>remote_addr</replaceable> |
| </arg> |
| <arg choice="opt" rep="norepeat"> |
| <replaceable>:port</replaceable> |
| </arg> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>protocol</replaceable> |
| </arg> |
| <arg choice="opt" rep="norepeat">-c<arg choice="req" rep="norepeat"><replaceable>time</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-i<arg choice="req" rep="norepeat"><replaceable>time</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-t<arg choice="req" rep="norepeat"><replaceable>val</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-S<arg choice="req" rep="norepeat"><replaceable>size</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-r<arg choice="req" rep="norepeat"><replaceable>size</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-k<arg choice="req" rep="norepeat"><replaceable>count</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-e<arg choice="req" rep="norepeat"><replaceable>max_epoch_size</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-b<arg choice="req" rep="norepeat"><replaceable>max_buffers</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-m</arg> |
| <arg choice="opt" rep="norepeat">-a<arg choice="req" rep="norepeat"><replaceable>hash_alg</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-x<arg choice="req" rep="norepeat"><replaceable>shared_secret</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-A<arg choice="req" rep="norepeat"><replaceable>asb-0p-policy</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-B<arg choice="req" rep="norepeat"><replaceable>asb-1p-policy</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-C<arg choice="req" rep="norepeat"><replaceable>asb-2p-policy</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-D</arg> |
| <arg choice="opt" rep="norepeat">-R<arg choice="req" rep="norepeat"><replaceable>role-resync-conflict-policy</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-p<arg choice="req" rep="norepeat"><replaceable>ping_timeout</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-u<arg choice="req" rep="norepeat"><replaceable>val</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-d<arg choice="req" rep="norepeat"><replaceable>hash_alg</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-o</arg> |
| <arg choice="opt" rep="norepeat">-n</arg> |
| <arg choice="opt" rep="norepeat">-g<arg choice="req" rep="norepeat"><replaceable>congestion_policy</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-f<arg choice="req" rep="norepeat"><replaceable>val</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-h<arg choice="req" rep="norepeat"><replaceable>val</replaceable></arg></arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">syncer</arg> |
| <arg choice="opt" rep="norepeat">-a<arg choice="req" rep="norepeat"><replaceable>dev_minor</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-r<arg choice="req" rep="norepeat"><replaceable>rate</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-e<arg choice="req" rep="norepeat"><replaceable>extents</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-v<arg choice="req" rep="norepeat"><replaceable>verify-hash-alg</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-c<arg choice="req" rep="norepeat"><replaceable>cpu-mask</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-C<arg choice="req" rep="norepeat"><replaceable>csums-hash-alg</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-R</arg> |
| <arg choice="opt" rep="norepeat">-p<arg choice="req" rep="norepeat"><replaceable>plan_time</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-s<arg choice="req" rep="norepeat"><replaceable>fill_target</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-d<arg choice="req" rep="norepeat"><replaceable>delay_target</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-m<arg choice="req" rep="norepeat"><replaceable>max_rate</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-n<arg choice="req" rep="norepeat"><replaceable>ond-policy</replaceable></arg></arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">disconnect</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">detach</arg> |
| <arg choice="opt" rep="norepeat">-f</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">down</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">primary</arg> |
| <arg choice="opt" rep="norepeat">-f</arg> |
| <arg choice="opt" rep="norepeat">-o</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">secondary</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">verify</arg> |
| <arg choice="opt" rep="norepeat">-s<arg choice="req" rep="norepeat"><replaceable>start-position</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-S<arg choice="req" rep="norepeat"><replaceable>stop-position</replaceable></arg></arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">invalidate</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">invalidate-remote</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">wait-connect</arg> |
| <arg choice="opt" rep="norepeat">-t<arg choice="req" rep="norepeat"><replaceable>wfc_timeout</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-d<arg choice="req" rep="norepeat"><replaceable>degr_wfc_timeout</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-o<arg choice="req" rep="norepeat"><replaceable>outdated_wfc_timeout</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-w</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">wait-sync</arg> |
| <arg choice="opt" rep="norepeat">-t<arg choice="req" rep="norepeat"><replaceable>wfc_timeout</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-d<arg choice="req" rep="norepeat"><replaceable>degr_wfc_timeout</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-o<arg choice="req" rep="norepeat"><replaceable>outdated_wfc_timeout</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-w</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">role</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">cstate</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">dstate</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">status</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">resize</arg> |
| <arg choice="opt" rep="norepeat">-d<arg choice="req" rep="norepeat"><replaceable>size</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-f<arg choice="req" rep="norepeat"><replaceable>assume-peer-has-space</replaceable></arg></arg> |
| <arg choice="opt" rep="norepeat">-c<arg choice="req" rep="norepeat"><replaceable>assume-clean</replaceable></arg></arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">check-resize</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">pause-sync</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">resume-sync</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">outdate</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">show-gi</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">get-gi</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">show</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">suspend-io</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">resume-io</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">events</arg> |
| <arg choice="opt" rep="norepeat">-u</arg> |
| <arg choice="opt" rep="norepeat">-a</arg> |
| </cmdsynopsis> |
| <cmdsynopsis sepchar=" "> |
| <command moreinfo="none">drbdsetup</command> |
| <arg choice="req" rep="norepeat"> |
| <replaceable>device</replaceable> |
| </arg> |
| <arg choice="plain" rep="norepeat">new-current-uuid</arg> |
| <arg choice="opt" rep="norepeat">-c</arg> |
| </cmdsynopsis> |
| </refsynopsisdiv> |
| <refsect1> |
| <title>Description</title> |
| <para> drbdsetup is used to associate DRBD devices with their backing |
| block devices, to set up DRBD device pairs to mirror their |
| backing block devices, and to inspect the configuration of |
| running DRBD devices. |
| </para> |
| </refsect1> |
| <refsect1> |
| <title>Note</title> |
| <para> drbdsetup is a low level tool of the DRBD program suite. It is |
| used by the data disk and drbd scripts to communicate with |
| the device driver. |
| </para> |
| </refsect1> |
| <refsect1> |
| <title>Commands</title> |
| <para> Each drbdsetup sub-command might require arguments and bring its own |
| set of options. All values have default units which might be overruled |
| by K, M or G. These units are defined in the usual way (e.g. K = 2^10 = 1024). |
| </para> |
| <refsect2> |
| <title>Common options</title> |
| <para> All drbdsetup sub-commands accept these two options |
| |
| <variablelist><varlistentry><term><option>--create-device</option></term><listitem><para> In case the specified DRBD device (minor number) does not |
| exist yet, create it implicitly. |
| </para></listitem></varlistentry><varlistentry><term><option>--set-defaults</option></term><listitem><para> When <option>--set-defaults</option> is given on the |
| command line, all options of the invoked sub-command that |
| are not explicitly set are reset to their default values. |
| </para></listitem></varlistentry></variablelist> |
| |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>disk</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>disk</secondary> |
| </indexterm> |
| <para> Associates <replaceable>device</replaceable> with |
| <replaceable>lower_device</replaceable> to store its data blocks on. |
| The <option>-d</option> (or <option>--disk-size</option>) should |
| only be used if you wish not to use as much as possible from the |
| backing block devices. |
| If you do not use <option>-d</option>, the <replaceable>device</replaceable> |
| is only ready for use as soon as it was connected to its peer once. |
| (See the <option>net</option> command.) |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term><option>-d</option>, |
| <option>--disk-size <replaceable>size</replaceable></option></term> |
| <listitem> |
| <para> You can override DRBD's size determination method with this |
| option. If you need to use the device before it was ever |
| connected to its peer, use this option to pass the |
| <replaceable>size</replaceable> of the DRBD device to the |
| driver. Default unit is sectors (1s = 512 bytes). |
| </para> |
| <para> If you use the <replaceable>size</replaceable> parameter in drbd.conf, |
| we strongly recommend to add an explicit unit postfix. |
| drbdadm and drbdsetup used to have mismatching default units. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-e</option>, |
| <option>--on-io-error <replaceable>err_handler</replaceable></option></term> |
| <listitem> |
| <para> If the driver of the <replaceable>lower_device</replaceable> |
| reports an error to DRBD, DRBD will mark the disk as inconsistent, |
| call a helper |
| program, or detach the device from its backing storage and |
| perform all further IO by requesting it from the peer. The |
| valid <replaceable>err_handlers</replaceable> are: |
| <option>pass_on</option>, <option>call-local-io-error</option> |
| and <option>detach</option>. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-f</option>, |
| <option>--fencing <replaceable>fencing_policy</replaceable></option></term> |
| <listitem> |
| <para> Under <option>fencing</option> we understand preventive |
| measures to avoid situations where both nodes are primary |
| and disconnected (AKA split brain). |
| </para> |
| <para> Valid fencing policies are: |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term> |
| <option>dont-care</option> |
| </term> |
| <listitem> |
| <para> This is the default policy. No fencing actions are done. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>resource-only</option> |
| </term> |
| <listitem> |
| <para> If a node becomes a disconnected primary, it tries to outdate |
| the peer's disk. This is done by calling the fence-peer |
| handler. The handler is supposed to reach the other node over |
| alternative communication paths and call 'drbdadm outdate |
| res' there. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>resource-and-stonith</option> |
| </term> |
| <listitem> |
| <para> If a node becomes a disconnected primary, it freezes all |
| its IO operations and calls its fence-peer handler. The |
| fence-peer handler is supposed to reach the peer over |
| alternative communication paths and call 'drbdadm outdate |
| res' there. In case it cannot reach the peer, it should |
| stonith the peer. IO is resumed as soon as the situation |
| is resolved. In case your handler fails, you can resume |
| IO with the <option>resume-io</option> command. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-b</option>, |
| <option>--use-bmbv</option></term> |
| <listitem> |
| <para> In case the backing storage's driver has a merge_bvec_fn() |
| function, DRBD has to |
| pretend that it can only process IO requests in units |
| not larger than 4 KiB. (At time of writing the only known |
| drivers which |
| have such a function are: md (software raid driver), |
| dm (device mapper - LVM) and DRBD itself)</para> |
| <para> To get best performance out of DRBD on top of software |
| raid (or any other driver with a merge_bvec_fn() function) |
| you might enable this option, if you know for sure |
| that the merge_bvec_fn() function will deliver the same |
| results on all nodes of your cluster. I.e. the physical |
| disks of the software raid are exactly of the same type. |
| USE THIS OPTION ONLY IF YOU KNOW WHAT YOU ARE DOING.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-a</option>, <option>--no-disk-barrier</option></term> |
| <term><option>-i</option>, <option>--no-disk-flushes</option></term> |
| <term><option>-D</option>, <option>--no-disk-drain</option></term> |
| <listitem> |
| <para> DRBD has four implementations to express write-after-write dependencies to |
| its backing storage device. DRBD will use the first method that is |
| supported by the backing storage device and that is not disabled by the user. |
| </para> |
| <para> When selecting the method you should not only base your decision on the |
| measurable performance. In case your backing storage device has a volatile |
| write cache (plain disks, RAID of plain disks) you should use one |
| of the first two. In case your backing storage device has battery-backed |
| write cache you may go with option 3. |
| Option 4 (disable everything, use "none") <emphasis>is dangerous</emphasis> |
| on most IO stacks, may result in write-reordering, and if so, |
| can theoretically be the reason for data corruption, or disturb |
| the DRBD protocol, causing spurious disconnect/reconnect cycles. |
| <emphasis>Do not use</emphasis> <option>no-disk-drain</option>. |
| </para> |
| <para> Unfortunately device mapper (LVM) might not support barriers. |
| </para> |
| <para> The letter after "wo:" in /proc/drbd indicates with method is currently in |
| use for a device: b, f, d, n. The implementations: |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term>barrier</term> |
| <listitem> |
| <para> The first requires that the driver of the |
| backing storage device support barriers (called 'tagged command queuing' in |
| SCSI and 'native command queuing' in SATA speak). The use of this |
| method can be disabled by the <option>--no-disk-barrier</option> option. |
| Note: Since Linux-2.6.36 (or RHEL's 2.6.32) this method is disabled. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term>flush</term> |
| <listitem> |
| <para> The second requires that the backing device support disk flushes (called |
| 'force unit access' in the drive vendors speak). The use of this method |
| can be disabled using the <option>--no-disk-flushes</option> option. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term>drain</term> |
| <listitem> |
| <para> The third method is simply to let write requests drain before |
| write requests of a new reordering domain are issued. That was the |
| only implementation before 8.0.9. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term>none</term> |
| <listitem> |
| <para> The fourth method is to not express write-after-write dependencies to |
| the backing store at all, by also specifying <option>--no-disk-drain</option>. |
| This <emphasis>is dangerous</emphasis> |
| on most IO stacks, may result in write-reordering, and if so, |
| can theoretically be the reason for data corruption, or disturb |
| the DRBD protocol, causing spurious disconnect/reconnect cycles. |
| <emphasis>Do not use</emphasis> <option>--no-disk-drain</option>. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-m</option>, |
| <option>--no-md-flushes</option></term> |
| <listitem> |
| <para> Disables the use of disk flushes and barrier BIOs when |
| accessing the meta data device. See the notes |
| on <option>--no-disk-flushes</option>. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-s</option>, |
| <option>--max-bio-bvecs</option></term> |
| <listitem> |
| <para> In some special circumstances the device mapper stack manages to |
| pass BIOs to DRBD that violate the constraints that are set forth |
| by DRBD's merge_bvec() function and which have more than one bvec. |
| A known example is: |
| phys-disk -> DRBD -> LVM -> Xen -> missaligned partition (63) -> DomU FS. |
| Then you might see "bio would need to, but cannot, be split:" in |
| the Dom0's kernel log. </para> |
| <para> The best workaround is to proper align the partition within |
| the VM (E.g. start it at sector 1024). That costs 480 KiB of storage. |
| Unfortunately the default of most Linux partitioning tools is |
| to start the first partition at an odd number (63). Therefore |
| most distributions install helpers for virtual linux machines will |
| end up with missaligned partitions. |
| The second best workaround is to limit DRBD's max bvecs per BIO |
| (i.e., the <option>max-bio-bvecs</option> option) to 1, but that might cost performance.</para> |
| <para> The default value of <option>max-bio-bvecs</option> is 0, which means that |
| there is no user imposed limitation. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-t</option>, |
| <option>--disk-timeout <replaceable>disk_timeout</replaceable></option></term> |
| <listitem> |
| <para> If the driver of the <replaceable>lower_device</replaceable> |
| does not finish an IO request within <replaceable>disk_timeout</replaceable>, |
| DRBD considers the disk as failed. If DRBD is connected to a remote host, |
| it will reissue local pending IO requests to the peer, and ship all new |
| IO requests to the peer only. The disk state advances to diskless, as soon |
| as the backing block device has finished all IO requests.</para> |
| <para> The default value of is 0, which means that no timeout is enforced. |
| The default unit is 100ms. This option is available since 8.3.12. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect2> |
| <refsect2> |
| <title>net</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>net</secondary> |
| </indexterm> |
| <para> Sets up the <replaceable>device</replaceable> to listen on |
| <replaceable>af:local_addr:port</replaceable> for incoming connections |
| and to try to connect to <replaceable>af:remote_addr:port</replaceable>. |
| If <replaceable>port</replaceable> is omitted, 7788 is used as default. |
| If <replaceable>af</replaceable> is omitted <option>ipv4</option> gets |
| used. Other supported address families are <option>ipv6</option>, |
| <option>ssocks</option> for Dolphin Interconnect Solutions' "super sockets" |
| and <option>sdp</option> for Sockets Direct Protocol (Infiniband). |
| </para> |
| <para> On the TCP/IP link the specified <replaceable>protocol</replaceable> |
| is used. Valid protocol specifiers are A, B, and C.</para> |
| <para>Protocol A: write IO is reported as completed, if it has reached |
| local disk and local TCP send buffer.</para> |
| <para>Protocol B: write IO is reported as completed, if it has reached |
| local disk and remote buffer cache.</para> |
| <para>Protocol C: write IO is reported as completed, if it has |
| reached both local and remote disk.</para> |
| <variablelist> |
| <varlistentry> |
| <term><option>-c</option>, |
| <option>--connect-int <replaceable>time</replaceable></option></term> |
| <listitem> |
| <para> In case it is not possible to connect to the remote DRBD |
| device immediately, DRBD keeps on trying to connect. With |
| this option you can set the time between two retries. The |
| default value is 10 seconds, the unit is 1 second. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-i</option>, |
| <option>--ping-int <replaceable>time</replaceable></option></term> |
| <listitem> |
| <para> If the TCP/IP connection linking a DRBD device pair is idle |
| for more than <replaceable>time</replaceable> seconds, DRBD |
| will generate a keep-alive packet to check if its partner is |
| still alive. The default value is 10 seconds, the unit is 1 second. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-t</option>, |
| <option>--timeout <replaceable>val</replaceable></option></term> |
| <listitem> |
| <para> If the partner node fails to send an expected response packet |
| within <replaceable>val</replaceable> |
| tenths of a second, the partner node |
| is considered dead and therefore the TCP/IP connection is |
| abandoned. The default value is 60 (= 6 seconds). |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-S</option>, |
| <option>--sndbuf-size <replaceable>size</replaceable></option></term> |
| <listitem> |
| <para> The socket send buffer is used to store packets sent to the |
| secondary node, which are not yet acknowledged (from a network |
| point of view) by the secondary node. When using protocol A, |
| it might be necessary to increase the size of this data |
| structure in order to increase asynchronicity between primary |
| and secondary nodes. But keep in mind that more asynchronicity |
| is synonymous with more data loss in the case of a primary |
| node failure. Since 8.0.13 resp. 8.2.7 setting the <replaceable>size</replaceable> |
| value to 0 means that the kernel should autotune this. |
| The default <replaceable>size</replaceable> is |
| 0, i.e. autotune. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-r</option>, |
| <option>--rcvbuf-size <replaceable>size</replaceable></option></term> |
| <listitem> |
| <para> Packets received from the network are stored in the socket receive |
| buffer first. From there they are consumed by DRBD. Before 8.3.2 the |
| receive buffer's size was always set to the size of the socket |
| send buffer. Since 8.3.2 they can be tuned independently. |
| A value of 0 means that the kernel should autotune this. |
| The default <replaceable>size</replaceable> is |
| 0, i.e. autotune. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-k</option>, |
| <option>--ko-count <replaceable>count</replaceable></option></term> |
| <listitem> |
| <para> In case the secondary node fails to complete a single write |
| request for <replaceable>count</replaceable> times the |
| <replaceable>timeout</replaceable>, it is expelled from the |
| cluster, i.e. the primary node goes into StandAlone mode. |
| To disable this feature, you should explicitly set it to 0; defaults may change between versions. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-e</option>, <option>--max-epoch-size |
| <replaceable>val</replaceable></option></term> |
| <listitem> |
| <para> With this option the maximal number of write requests between |
| two barriers is limited. Typically set to the same as |
| <option>--max-buffers</option>, or the allowed maximum. |
| Values smaller than 10 can lead to degraded performance. |
| The default value is 2048. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-b</option>, |
| <option>--max-buffers <replaceable>val</replaceable></option></term> |
| <listitem> |
| <para> With this option the maximal number of buffer pages allocated |
| by DRBD's receiver thread is limited. Typically set to the |
| same as <option>--max-epoch-size</option>. Small values |
| could lead to degraded performance. The default value is 2048, the minimum 32. |
| Increase this if you cannot saturate the IO backend of the receiving side |
| during linear write or during resync while otherwise idle. |
| </para> |
| <para>See also <citerefentry><refentrytitle>drbd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry></para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-u</option>, |
| <option>--unplug-watermark <replaceable>val</replaceable></option></term> |
| <listitem> |
| <para> |
| This setting has no effect with recent kernels that use explicit on-stack |
| plugging (upstream Linux kernel 2.6.39, distributions may have backported). |
| </para> |
| <para> When the number of pending write requests on the standby |
| (secondary) node exceeds the unplug-watermark, we trigger |
| the request processing of our backing storage device. |
| Some storage controllers deliver better performance with small |
| values, others deliver best performance when the value is set to |
| the same value as max-buffers, yet others don't feel much effect at all. |
| Minimum 16, default 128, maximum 131072. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-m</option>, |
| <option>--allow-two-primaries </option></term> |
| <listitem> |
| <para> With this option set you may assign primary role to both nodes. You |
| only should use this option if you use a shared storage |
| file system on top of DRBD. At the time of writing the only |
| ones are: OCFS2 and GFS. If you use this option with any |
| other file system, you are going to crash your nodes and to |
| corrupt your data! |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-a</option>, |
| <option>--cram-hmac-alg </option><replaceable>alg</replaceable></term> |
| <listitem> |
| <para> You need to specify the HMAC algorithm to enable peer |
| authentication at all. You are strongly encouraged to use |
| peer authentication. |
| The HMAC algorithm will be used for the challenge |
| response authentication of the peer. You may specify any |
| digest algorithm that is named in /proc/crypto. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-x</option>, |
| <option>--shared-secret </option><replaceable>secret</replaceable></term> |
| <listitem> |
| <para> The shared secret used in peer authentication. May be up to |
| 64 characters. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-A</option>, |
| <option>--after-sb-0pri </option><replaceable>asb-0p-policy</replaceable></term> |
| <listitem> |
| <para> possible policies are: |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term> |
| <option>disconnect</option> |
| </term> |
| <listitem> |
| <para> No automatic resynchronization, simply disconnect. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>discard-younger-primary</option> |
| </term> |
| <listitem> |
| <para> Auto sync from the node that was primary before the split-brain situation occurred. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>discard-older-primary</option> |
| </term> |
| <listitem> |
| <para> Auto sync from the node that became primary as second during |
| the split-brain situation. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>discard-zero-changes</option> |
| </term> |
| <listitem> |
| <para> In case one node did not write anything since the split |
| brain became evident, sync from the node that wrote something |
| to the node that did not write anything. In case none wrote |
| anything this policy uses a random decision to perform |
| a "resync" of 0 blocks. In case both have written something |
| this policy disconnects the nodes. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>discard-least-changes</option> |
| </term> |
| <listitem> |
| <para> Auto sync from the node that touched more blocks during the |
| split brain situation. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>discard-node-NODENAME</option> |
| </term> |
| <listitem> |
| <para> Auto sync to the named node. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-B</option>, |
| <option>--after-sb-1pri </option><replaceable>asb-1p-policy</replaceable></term> |
| <listitem> |
| <para> possible policies are: |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term> |
| <option>disconnect</option> |
| </term> |
| <listitem> |
| <para> No automatic resynchronization, simply disconnect. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>consensus</option> |
| </term> |
| <listitem> |
| <para> Discard the version of the secondary if the outcome |
| of the <option>after-sb-0pri</option> algorithm would also |
| destroy the current secondary's data. Otherwise disconnect. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>discard-secondary</option> |
| </term> |
| <listitem> |
| <para> Discard the secondary's version. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>call-pri-lost-after-sb</option> |
| </term> |
| <listitem> |
| <para> Always honor the outcome of the <option>after-sb-0pri |
| </option> algorithm. In case it decides the current |
| secondary has the correct data, call the |
| <option>pri-lost-after-sb</option> on the current primary. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>violently-as0p</option> |
| </term> |
| <listitem> |
| <para> Always honor the outcome of the <option>after-sb-0pri |
| </option> algorithm. In case it decides the current |
| secondary has the correct data, accept a possible instantaneous |
| change of the primary's data. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-C</option>, |
| <option>--after-sb-2pri </option><replaceable>asb-2p-policy</replaceable></term> |
| <listitem> |
| <para> possible policies are: |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term> |
| <option>disconnect</option> |
| </term> |
| <listitem> |
| <para> No automatic resynchronization, simply disconnect. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>call-pri-lost-after-sb</option> |
| </term> |
| <listitem> |
| <para> Always honor the outcome of the <option>after-sb-0pri |
| </option> algorithm. In case it decides the current |
| secondary has the right data, call the |
| <option>pri-lost-after-sb</option> on the current primary. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term> |
| <option>violently-as0p</option> |
| </term> |
| <listitem> |
| <para> Always honor the outcome of the <option>after-sb-0pri |
| </option> algorithm. In case it decides the current |
| secondary has the right data, accept a possible instantaneous |
| change of the primary's data. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-P</option>, |
| <option>--always-asbp</option></term> |
| <listitem> |
| <para> Normally the automatic after-split-brain policies are only |
| used if current states of the UUIDs do not indicate the |
| presence of a third node. |
| </para> |
| <para> With this option you request that the automatic |
| after-split-brain policies are used as long as the data |
| sets of the nodes are somehow related. This might cause |
| a full sync, if the UUIDs indicate the presence of a third |
| node. (Or double faults have led to strange UUID sets.) |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-R</option>, |
| <option>--rr-conflict </option><replaceable>role-resync-conflict-policy</replaceable></term> |
| <listitem> |
| <para> This option sets DRBD's behavior when DRBD deduces from its |
| meta data that a resynchronization is needed, and the SyncTarget |
| node is already primary. The possible settings are: |
| <option>disconnect</option>, |
| <option>call-pri-lost</option> and |
| <option>violently</option>. While <option>disconnect</option> |
| speaks for itself, with the <option>call-pri-lost</option> |
| setting the <option>pri-lost</option> handler is called |
| which is expected to either change the role of the node to |
| secondary, or remove the node from the cluster. |
| The default is <option>disconnect</option>.</para> |
| <para> With the <option>violently</option> setting you allow DRBD |
| to force a primary node into SyncTarget state. This means |
| that the data exposed by DRBD changes to |
| the SyncSource's version of the data instantaneously. |
| USE THIS OPTION ONLY IF YOU KNOW WHAT YOU ARE DOING. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-d</option>, |
| <option>--data-integrity-alg </option><replaceable>hash_alg</replaceable></term> |
| <listitem> |
| <para> DRBD can ensure the data integrity of the user's data on the network |
| by comparing hash values. Normally this is ensured by the 16 bit checksums |
| in the headers of TCP/IP packets. This option |
| can be set to any of the kernel's data digest algorithms. |
| In a typical kernel configuration you should have |
| at least one of <option>md5</option>, <option>sha1</option>, and <option>crc32c</option> |
| available. By default this is not enabled. |
| </para> |
| <para>See also the notes on data integrity on the drbd.conf manpage.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-o</option>, |
| <option>--no-tcp-cork </option></term> |
| <listitem> |
| <para> DRBD usually uses the TCP socket option TCP_CORK to hint to the network |
| stack when it can expect more data, and when it should flush out what it |
| has in its send queue. There is at least one network |
| stack that performs worse when one uses this hinting method. Therefore |
| we introduced this option, which disable the setting and clearing of |
| the TCP_CORK socket option by DRBD. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-p</option>, |
| <option>--ping-timeout </option><replaceable>ping_timeout</replaceable></term> |
| <listitem> |
| <para> The time the peer has to answer to a keep-alive packet. In case the peer's reply is not received within this |
| time period, it is considered dead. The default unit is tenths of a second, |
| the default value is 5 (for half a second). |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-D</option>, |
| <option>--discard-my-data </option></term> |
| <listitem> |
| <para> Use this option to manually recover from a split-brain |
| situation. In case you do not have any automatic after-split-brain policies selected, the nodes refuse to |
| connect. By passing this option you make this node a |
| sync target immediately after successful connect. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-n</option>, |
| <option>--dry-run </option></term> |
| <listitem> |
| <para> Causes DRBD to abort the connection process after the resync |
| handshake, i.e. no resync gets performed. You can find out which resync |
| DRBD would perform by looking at the kernel's log file. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-g</option>, <option>--on-congestion </option><replaceable>congestion_policy</replaceable></term> |
| <term><option>-f</option>, <option>--congestion-fill </option><replaceable>fill_threshold</replaceable></term> |
| <term><option>-h</option>, <option>--congestion-extents </option><replaceable>active_extents_threshold</replaceable></term> |
| <listitem> |
| <para>By default DRBD blocks when the available TCP send queue becomes full. |
| That means it will slow down the application that generates the write |
| requests that cause DRBD to send more data down that TCP connection. |
| </para> |
| <para>When DRBD is deployed with DRBD-proxy it might be more desirable that |
| DRBD goes into AHEAD/BEHIND mode shortly before the send queue becomes full. |
| In AHEAD/BEHIND mode DRBD does no longer replicate data, but still keeps |
| the connection open.</para> |
| <para>The advantage of the AHEAD/BEHIND mode is that the |
| application is not slowed down, even if DRBD-proxy's buffer is |
| not sufficient to buffer all write requests. The downside is that |
| the peer node falls behind, and that a resync will be necessary to |
| bring it back into sync. During that resync the peer node will have |
| an inconsistent disk. </para> |
| <para>Available <replaceable>congestion_policy</replaceable>s are <option>block</option> |
| and <option>pull-ahead</option>. The default is <option>block</option>. |
| <replaceable>Fill_threshold</replaceable> might be in the range of 0 to 10GiBytes. The |
| default is 0 which disables the check. <replaceable>Active_extents_threshold</replaceable> |
| has the same limits as <option>al-extents</option>.</para> |
| <para>The AHEAD/BEHIND mode and its settings are available since DRBD 8.3.10.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect2> |
| <refsect2> |
| <title>syncer</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>syncer</secondary> |
| </indexterm> |
| <para> Changes the synchronization daemon parameters of |
| <replaceable>device</replaceable> at runtime. |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term><option>-r</option>, |
| <option>--rate <replaceable>rate</replaceable></option></term> |
| <listitem> |
| <para> To ensure smooth operation of the application on top of DRBD, |
| it is possible to limit the bandwidth that may be used by |
| background synchronization. The default is 250 KiB/sec, the |
| default unit is KiB/sec. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-a</option>, |
| <option>--after <replaceable>minor</replaceable></option></term> |
| <listitem> |
| <para> Start resync on this device only if the device with |
| <replaceable>minor</replaceable> is already in connected |
| state. Otherwise this device waits in SyncPause state. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-e</option>, |
| <option>--al-extents <replaceable>extents</replaceable></option></term> |
| <listitem> |
| <para> DRBD automatically performs hot area detection. With this |
| parameter you control how big the hot area (=active set) can |
| get. Each extent marks 4M of the backing storage. In case a |
| primary node leaves the cluster unexpectedly, the areas covered |
| by the active set must be resynced upon rejoining of the failed |
| node. The data structure is stored in the meta-data area, |
| therefore each change of the active set is a write operation |
| to the meta-data device. A higher number of extents gives |
| longer resync times but less updates to the meta-data. The |
| default number of <replaceable>extents</replaceable> is |
| 127. (Minimum: 7, Maximum: 3843) |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-v</option>, |
| <option>--verify-alg <replaceable>hash-alg</replaceable></option></term> |
| <listitem> |
| <para> During online verification (as initiated by the |
| <command moreinfo="none">verify</command> sub-command), |
| rather than doing a bit-wise comparison, DRBD applies a hash function |
| to the contents of every block being verified, and compares that |
| hash with the peer. This option defines the hash algorithm being |
| used for that purpose. It can be set to any of the kernel's data |
| digest algorithms. In a typical kernel configuration you should have |
| at least one of <option>md5</option>, <option>sha1</option>, and <option>crc32c</option> |
| available. By default this is not enabled; you must set this |
| option explicitly in order to be able to use on-line device verification. |
| </para> |
| <para>See also the notes on data integrity on the drbd.conf manpage.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-c</option>, |
| <option>--cpu-mask <replaceable>cpu-mask</replaceable></option></term> |
| <listitem> |
| <para> Sets the cpu-affinity-mask for DRBD's kernel threads of this |
| device. The default value of <replaceable>cpu-mask</replaceable> is |
| 0, which means that DRBD's kernel threads should be spread over |
| all CPUs of the machine. This value must be given in hexadecimal |
| notation. If it is too big it will be truncated. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-C</option>, |
| <option>--csums-alg <replaceable>hash-alg</replaceable></option></term> |
| <listitem> |
| <para> A resync process sends all marked data blocks form the source to |
| the destination node, as long as no <option>csums-alg</option> is |
| given. When one is specified the resync process exchanges hash values of all |
| marked blocks first, and sends only those data blocks over, that have different |
| hash values.</para> |
| <para>This setting is useful for DRBD setups with low bandwidth links. |
| During the restart of a crashed primary node, all blocks covered by the |
| activity log are marked for resync. But a large part of those will actually |
| be still in sync, therefore using <option>csums-alg</option> will lower |
| the required bandwidth in exchange for CPU cycles. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-R</option>, |
| <option>--use-rle</option></term> |
| <listitem> |
| <para> During resync-handshake, the dirty-bitmaps of the nodes are |
| exchanged and merged (using bit-or), so the nodes will have the |
| same understanding of which blocks are dirty. On large devices, |
| the fine grained dirty-bitmap can become large as well, and the |
| bitmap exchange can take quite some time on low-bandwidth links. |
| </para> |
| <para> Because the bitmap typically contains compact areas where all |
| bits are unset (clean) or set (dirty), a simple run-length |
| encoding scheme can considerably reduce the network traffic |
| necessary for the bitmap exchange. |
| </para> |
| <para> For backward compatibilty reasons, and because on fast links this |
| possibly does not improve transfer time but consumes cpu cycles, |
| this defaults to off. |
| </para> |
| <para> Introduced in 8.3.2. |
| </para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-p</option>, |
| <option>--c-plan-ahead <replaceable>plan_time</replaceable></option></term> |
| <term><option>-s</option>, |
| <option>--c-fill-target <replaceable>fill_target</replaceable></option></term> |
| <term><option>-d</option>, |
| <option>--c-delay-target <replaceable>delay_target</replaceable></option></term> |
| <term><option>-M</option>, |
| <option>--c-max-rate <replaceable>max_rate</replaceable></option></term> |
| <listitem> |
| <para>The dynamic resync speed controller gets enabled with setting |
| <replaceable>plan_time</replaceable> to a positive value. It aims to |
| fill the buffers along the data path with either a constant amount of data |
| <replaceable>fill_target</replaceable>, or aims to have a constant |
| delay time of <replaceable>delay_target</replaceable> along the |
| path. The controller has an upper bound of <replaceable>max_rate</replaceable>. |
| </para> |
| <para> |
| By <replaceable>plan_time</replaceable> the agility of the controller is configured. |
| Higher values yield for slower/lower responses of the controller to deviation |
| from the target value. It should be at least 5 times RTT. |
| For regular data paths a <replaceable>fill_target</replaceable> |
| in the area of 4k to 100k is appropriate. For a setup that contains drbd-proxy |
| it is advisable to use <replaceable>delay_target</replaceable> instead. |
| Only when <replaceable>fill_target</replaceable> is set to 0 the controller |
| will use <replaceable>delay_target</replaceable>. 5 times RTT is a reasonable |
| starting value. <replaceable>Max_rate</replaceable> should be set to the |
| bandwidth available between the DRBD-hosts and the machines hosting |
| DRBD-proxy, or to the available disk-bandwidth. |
| </para> |
| <para> |
| The default value of <replaceable>plan_time</replaceable> is 0, the default unit is |
| 0.1 seconds. <replaceable>Fill_target</replaceable> has 0 and sectors as default unit. |
| <replaceable>Delay_target</replaceable> has 1 (100ms) and 0.1 as default unit. |
| <replaceable>Max_rate</replaceable> has 10240 (100MiB/s) and KiB/s as default unit. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-m</option>, |
| <option>--c-min-rate <replaceable>min_rate</replaceable></option></term> |
| <listitem> |
| <para>We track the disk IO rate caused by the resync, so we can |
| detect non-resync IO on the lower level device. If the lower |
| level device seems to be busy, and the current resync rate is |
| above <replaceable>min_rate</replaceable>, we throttle the resync. |
| </para> |
| <para> |
| The default value of <replaceable>min_rate</replaceable> is 4M, |
| the default unit is k. If you want to not throttle at all, set |
| it to zero, if you want to throttle always, set it to one. |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-n</option>, |
| <option>--on-no-data-accessible <replaceable>ond-policy</replaceable></option></term> |
| <listitem> |
| <para>This setting controls what happens to IO requests on a degraded, disk less node |
| (I.e. no data store is reachable). The available policies are <option>io-error</option> |
| and <option>suspend-io</option>.</para> |
| <para> |
| If <replaceable>ond-policy</replaceable> is set to <option>suspend-io</option> you |
| can either resume IO by attaching/connecting the last lost data storage, or by |
| the <command moreinfo="none">drbdadm resume-io <replaceable>res</replaceable></command> |
| command. The latter will result in IO errors of course. |
| </para> |
| <para> |
| The default is <option>io-error</option>. This setting is available since DRBD 8.3.9. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect2> |
| <refsect2> |
| <title>primary</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>primary</secondary> |
| </indexterm> |
| <para> Sets the <replaceable>device</replaceable> into primary role. This |
| means that applications (e.g. a file system) may open the |
| <replaceable>device</replaceable> for read and write access. Data |
| written to the <replaceable>device</replaceable> in primary role are |
| mirrored to the device in secondary role. |
| </para> |
| <para> Normally it is not possible to set both devices of a connected DRBD device |
| pair to primary role. By using the <option>--allow-two-primaries</option> |
| option, you override this behavior and instruct DRBD to allow two |
| primaries. |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term><option>-o</option>, |
| <option>--overwrite-data-of-peer</option></term> |
| <listitem> |
| <para>Alias for --force. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| <variablelist> |
| <varlistentry> |
| <term><option>-f</option>, |
| <option>--force</option></term> |
| <listitem> |
| <para> Becoming primary fails if the local replica is |
| not up-to-date. I.e. when it is inconsistent, outdated of consistent. |
| By using this option you can force it into |
| primary role anyway. USE THIS OPTION ONLY IF YOU KNOW WHAT |
| YOU ARE DOING. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect2> |
| <refsect2> |
| <title>secondary</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>secondary</secondary> |
| </indexterm> |
| <para> Brings the <replaceable>device</replaceable> into secondary role. |
| This operation fails as long as at least one application (or file |
| system) has opened the device. |
| </para> |
| <para> It is possible that both devices of a connected DRBD device pair are secondary. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>verify</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>verify</secondary> |
| </indexterm> |
| <para> This initiates on-line device verification. During on-line verification, |
| the contents of every block on the local node are compared to those on |
| the peer node. Device verification progress can be monitored via |
| <filename moreinfo="none">/proc/drbd</filename>. |
| Any blocks whose content differs from that of the corresponding block |
| on the peer node will be marked out-of-sync in DRBD's on-disk bitmap; they |
| are <emphasis>not</emphasis> brought back in sync automatically. To |
| do that, simply disconnect and reconnect the resource. |
| </para> |
| <para>If on-line verification is already in progress (and this node is "VerifyS"), |
| this command silently "succeeds". In this case, any start-sector (see |
| below) will be ignored, and any stop-sector (see below) will be honored. |
| This can be used to stop a running verify, or to update/shorten/extend |
| the coverage of the currently running verify. |
| </para> |
| <para> This command will fail if the <replaceable>device</replaceable> is |
| not part of a connected device pair. |
| </para> |
| <para>See also the notes on data integrity on the drbd.conf manpage.</para> |
| <variablelist> |
| <varlistentry> |
| <term><option>-s</option>, |
| <option>--start <replaceable>start-sector</replaceable></option></term> |
| <listitem> |
| <para>Since version 8.3.2, on-line verification should resume from the |
| last position after connection loss. It may also be started from |
| an arbitrary position by setting this option. If you had reached some |
| stop-sector before, and you do not specify an explicit start-sector, |
| verify should resume from the previous stop-sector. |
| </para> |
| <para>Default unit is sectors. You may also specify a unit explicitly. |
| The <option>start-sector</option> will be rounded down to a multiple of 8 sectors (4kB). |
| </para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option>-S</option>, |
| <option>--stop <replaceable>stop-sector</replaceable></option></term> |
| <listitem> |
| <para>Since version 8.3.14, on-line verification can be stopped |
| before it reaches end-of-device. This can be |
| </para> |
| <para>Default unit is sectors. You may also specify a unit explicitly. |
| The <option>stop-sector</option> may be updated by issuing an additional |
| drbdsetup verify command on the same node while the verify is running. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect2> |
| <refsect2> |
| <title>invalidate</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>invalidate</secondary> |
| </indexterm> |
| <para> This forces the local device of a pair of connected DRBD devices |
| into SyncTarget state, which means that all data blocks of the |
| device are copied over from the peer. |
| </para> |
| <para> This command will fail if the <replaceable>device</replaceable> is |
| not either part of a connected device pair, or disconnected Secondary. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>invalidate-remote</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>invalidate-remote</secondary> |
| </indexterm> |
| <para> This forces the local device of a pair of connected DRBD devices |
| into SyncSource state, which means that all data blocks of the |
| device are copied to the peer. |
| </para> |
| <para> |
| On a disconnected Primary device, this will set all bits in the out of sync bitmap. |
| As a side affect this suspends updates to the on disk activity log. Updates |
| to the on disk activity log resume automatically when necessary. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>wait-connect</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>wait-connect</secondary> |
| </indexterm> |
| <para> Returns as soon as the <replaceable>device</replaceable> can |
| communicate with its partner device. |
| </para> |
| <variablelist> |
| <varlistentry> |
| <term><option>-t</option>, |
| <option>--wfc-timeout <replaceable>wfc_timeout</replaceable></option></term> |
| <term><option>-d</option>, |
| <option>--degr-wfc-timeout <replaceable>degr_wfc_timeout</replaceable></option></term> |
| <term><option>-o</option>, |
| <option>--outdated-wfc-timeout <replaceable>outdated_wfc_timeout</replaceable></option></term> |
| <term><option>-w</option>, <option>--wait-after-sb</option></term> |
| <listitem> |
| <para> This command will fail if the |
| <replaceable>device</replaceable> cannot communicate with its |
| partner for <replaceable>timeout</replaceable> |
| seconds. If the peer was working before this node was |
| rebooted, the <replaceable>wfc_timeout</replaceable> is used. If the peer was already |
| down before this node was rebooted, the <replaceable>degr_wfc_timeout</replaceable> |
| is used. If the peer was sucessfully outdated before this |
| node was rebooted the <replaceable>outdated_wfc_timeout</replaceable> is used. |
| The default value for all those timeout values |
| is 0 which means to wait forever. |
| In case the connection status goes down to StandAlone because |
| the peer appeared but the devices had a split brain situation, |
| the default for the command is to terminate. You can change this |
| behavior with the <option>--wait-after-sb</option> option. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect2> |
| <refsect2> |
| <title>wait-sync</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>wait-sync</secondary> |
| </indexterm> |
| <para> Returns as soon as the <replaceable>device</replaceable> leaves any |
| synchronization into connected state. The options |
| are the same as with the <replaceable>wait-connect</replaceable> |
| command. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>disconnect</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>disconnect</secondary> |
| </indexterm> |
| <para> Removes the information set by the <option>net</option> command |
| from the <replaceable>device</replaceable>. This means |
| that the <replaceable>device</replaceable> goes into unconnected |
| state and will no longer listen for incoming connections. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>detach</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>detach</secondary> |
| </indexterm> |
| <para> Removes the information set by the <option>disk</option> command |
| from the <replaceable>device</replaceable>. This means |
| that the <replaceable>device</replaceable> is detached from its |
| backing storage device. |
| <variablelist> |
| <varlistentry> |
| <term><option>-f</option>, |
| <option>--force</option></term> |
| <listitem> |
| <para>A regular detach returns after the disk state finally reached |
| diskless. As a consequence detaching from a frozen backing block device |
| never terminates.</para> |
| <para>On the other hand A forced detach returns immediately. It allows |
| you to detach DRBD from a frozen backing block device. Please note that |
| the disk will be marked as failed until all pending IO requests where |
| finished by the backing block device. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>down</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>down</secondary> |
| </indexterm> |
| <para> Removes all configuration information from the |
| <replaceable>device</replaceable> and forces it back to |
| unconfigured state. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>role</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>role</secondary> |
| </indexterm> |
| <para> Shows the current roles of the <replaceable>device</replaceable> and |
| its peer, as <replaceable>local</replaceable>/<replaceable>peer</replaceable>. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>state</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>state</secondary> |
| </indexterm> |
| <para>Deprecated alias for "role"</para> |
| </refsect2> |
| <refsect2> |
| <title>cstate</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>cstate</secondary> |
| </indexterm> |
| <para> Shows the current connection state of the |
| <replaceable>device</replaceable>. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>dstate</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>dstate</secondary> |
| </indexterm> |
| <para> Shows the current states of the backing storage devices, as <replaceable>local</replaceable>/<replaceable>peer</replaceable>. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>status</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>status</secondary> |
| </indexterm> |
| <para> Shows the current status of the device in XML-like format. Example output: |
| <programlisting format="linespecific"><resource minor="0" name="s0" cs="SyncTarget" st1="Secondary" st2="Secondary" |
| ds1="Inconsistent" ds2="UpToDate" resynced_precent="5.9" /></programlisting> |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>resize</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>resize</secondary> |
| </indexterm> |
| <para>This causes DRBD to reexamine the size of the |
| <replaceable>device</replaceable>'s backing storage device. To |
| actually do online growing you need to extend the backing storages |
| on both devices and call the <option>resize</option> command on one of |
| your nodes. |
| </para> |
| <para>The <option>--assume-peer-has-space</option> allows you to |
| resize a device which is currently not connected to the peer. |
| Use with care, since if you do not resize the peer's disk as well, |
| further connect attempts of the two will fail. |
| </para> |
| <para>When the <option>--assume-clean</option> option is given |
| DRBD will skip the resync of the new storage. Only do this if you |
| know that the new storage was initialized to the same content |
| by other means. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>check-resize</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>check-resize</secondary> |
| </indexterm> |
| <para>To enable DRBD to detect offline resizing of backing devices |
| this command may be used to record the current size of backing |
| devices. The size is stored in files in /var/lib/drbd/ named |
| drbd-minor-??.lkbd |
| </para> |
| <para> |
| This command is called by |
| <command moreinfo="none">drbdadm resize <replaceable>res</replaceable></command> after |
| <command moreinfo="none">drbdsetup <replaceable>device</replaceable> resize</command> returned. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>pause-sync</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>pause-sync</secondary> |
| </indexterm> |
| <para> Temporarily suspend an ongoing resynchronization by setting the local |
| pause flag. Resync only progresses if neither the local nor the |
| remote pause flag is set. It might be desirable to postpone DRBD's |
| resynchronization after eventual resynchronization of the backing |
| storage's RAID setup. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>resume-sync</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>resume-sync</secondary> |
| </indexterm> |
| <para> Unset the local sync pause flag. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>outdate</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>outdate</secondary> |
| </indexterm> |
| <para> Mark the data on the local backing storage as outdated. An outdated |
| device refuses to become primary. This is used in conjunction with |
| <option>fencing</option> and by the peer's <option>fence-peer</option> handler. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>show-gi</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>show-gi</secondary> |
| </indexterm> |
| <para> Displays the device's data generation identifiers verbosely. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>get-gi</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>get-gi</secondary> |
| </indexterm> |
| <para> Displays the device's data generation identifiers. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>show</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>show</secondary> |
| </indexterm> |
| <para> Shows all available configuration information of the |
| <replaceable>device</replaceable>. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>suspend-io</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>suspend-io</secondary> |
| </indexterm> |
| <para> This command is of no apparent use and just provided for the sake |
| of completeness. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>resume-io</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>resume-io</secondary> |
| </indexterm> |
| <para> If the fence-peer handler fails to stonith the peer node, |
| and your <option>fencing</option> policy is set to |
| resource-and-stonith, you can unfreeze IO operations with this |
| command. |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>events</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>events</secondary> |
| </indexterm> |
| <para> Displays every state change of DRBD and all calls to helper |
| programs. This might be used to get notified of DRBD's state |
| changes by piping the output to another program. |
| |
| <variablelist><varlistentry><term><option>-a</option>, |
| <option>--all-devices</option></term><listitem><para> Display the events of all DRBD minors. |
| </para></listitem></varlistentry><varlistentry><term><option>-u</option>, |
| <option>--unfiltered</option></term><listitem><para> This is a debugging aid that displays the content of |
| all received netlink messages. |
| </para></listitem></varlistentry></variablelist> |
| </para> |
| </refsect2> |
| <refsect2> |
| <title>new-current-uuid</title> |
| <indexterm significance="normal"> |
| <primary>drbdsetup</primary> |
| <secondary>new-current-uuid</secondary> |
| </indexterm> |
| <para> Generates a new current UUID and rotates all other UUID values. This |
| has at least two use cases, namely to skip the initial sync, and to |
| reduce network bandwidth when starting in a single node configuration |
| and then later (re-)integrating a remote site. |
| </para> |
| <para> Available option: |
| |
| <variablelist><varlistentry><term><option>-c</option>, |
| <option>--clear-bitmap</option></term><listitem><para> Clears the sync bitmap in addition to generating a new current UUID. |
| </para></listitem></varlistentry></variablelist> |
| </para> |
| <para> This can be used to skip the initial sync, if you want to start from scratch. |
| This use-case does only work on "Just Created" meta data. |
| Necessary steps: |
| <orderedlist numeration="arabic" inheritnum="ignore" continuation="restarts"><listitem><simpara> On <emphasis>both</emphasis> nodes, initialize meta data and configure the device. |
| </simpara><simpara><command moreinfo="none">drbdadm -- --force create-md <replaceable>res</replaceable></command></simpara></listitem><listitem><simpara> They need to do the initial handshake, so they know their sizes. |
| </simpara><simpara><command moreinfo="none">drbdadm up <replaceable>res</replaceable></command></simpara></listitem><listitem><simpara> They are now Connected Secondary/Secondary Inconsistent/Inconsistent. |
| Generate a new current-uuid and clear the dirty bitmap. |
| </simpara><simpara><command moreinfo="none">drbdadm -- --clear-bitmap new-current-uuid <replaceable>res</replaceable></command></simpara></listitem><listitem><simpara> They are now Connected Secondary/Secondary UpToDate/UpToDate. |
| Make one side primary and create a file system. |
| </simpara><simpara><command moreinfo="none">drbdadm primary <replaceable>res</replaceable></command></simpara><simpara><command moreinfo="none">mkfs -t <replaceable>fs-type</replaceable> $(drbdadm sh-dev <replaceable>res</replaceable>)</command></simpara></listitem></orderedlist> |
| </para> |
| <para> One obvious side-effect is that the replica is full of old garbage |
| (unless you made them identical using other means), so any |
| online-verify is expected to find any number of out-of-sync blocks. |
| </para> |
| <para><emphasis>You must not use this on pre-existing data!</emphasis> |
| Even though it may appear to work at first glance, once you switch to |
| the other node, your data is toast, as it never got replicated. |
| So <emphasis>do not leave out the mkfs</emphasis> (or equivalent). |
| </para> |
| <para> This can also be used to shorten the initial resync of a cluster where the second node |
| is added after the first node is gone into production, by means of disk shipping. |
| This use-case works on disconnected devices only, the device may be in |
| primary or secondary role. |
| </para> |
| <para>The necessary steps on the current active server are: |
| <orderedlist numeration="arabic" inheritnum="ignore" continuation="restarts"><listitem><simpara><command moreinfo="none">drbdsetup <replaceable>device</replaceable> new-current-uuid --clear-bitmap</command></simpara></listitem><listitem><simpara> Take the copy of the current active server. E.g. by pulling a disk out of |
| the RAID1 controller, or by copying with dd. You need to copy the actual |
| data, and the meta data. |
| </simpara></listitem><listitem><simpara><command moreinfo="none">drbdsetup <replaceable>device</replaceable> new-current-uuid</command></simpara></listitem></orderedlist> |
| Now add the disk to the new secondary node, and join it to the cluster. You will |
| get a resync of that parts that were changed since the first call to |
| <command moreinfo="none">drbdsetup</command> in step 1. |
| </para> |
| </refsect2> |
| </refsect1> |
| <refsect1> |
| <title>Examples</title> |
| <para> For examples, please have a look at the |
| <ulink url="http://www.drbd.org/users-guide/"><citetitle>DRBD User's Guide</citetitle></ulink>. |
| </para> |
| </refsect1> |
| <refsect1> |
| <title>Version</title> |
| <simpara>This document was revised for version 8.3.2 of the DRBD distribution. |
| </simpara> |
| </refsect1> |
| <refsect1> |
| <title>Author</title> |
| <simpara>Written by Philipp Reisner <email>philipp.reisner@linbit.com</email> |
| and Lars Ellenberg <email>lars.ellenberg@linbit.com</email> |
| </simpara> |
| </refsect1> |
| <refsect1> |
| <title>Reporting Bugs</title> |
| <simpara>Report bugs to <email>drbd-user@lists.linbit.com</email>. |
| </simpara> |
| </refsect1> |
| <refsect1> |
| <title>Copyright</title> |
| <simpara>Copyright 2001-2008 LINBIT Information Technologies, |
| Philipp Reisner, Lars Ellenberg. This is free software; |
| see the source for copying conditions. There is NO warranty; |
| not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| </simpara> |
| </refsect1> |
| <refsect1> |
| <title>See Also</title> |
| <para><citerefentry><refentrytitle>drbd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>drbd</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>drbddisk</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>drbdadm</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <ulink url="http://www.drbd.org/users-guide/"><citetitle>DRBD User's Guide</citetitle></ulink>, |
| <ulink url="http://www.drbd.org/"><citetitle>DRBD web site</citetitle></ulink></para> |
| </refsect1> |
| </refentry> |
