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 QLogic FC Target Driver How-to for 22xx/23xx/24xx/25xx/26xx Adapters
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   <div style="text-align: center;">
     <strong>How to Configure the FC QLogic Target Driver for
       22xx/23xx/24xx/25xx/26xx Adapters</strong></div>
   <br><br>

   <div style="text-align: center;"> <strong>TARGET SYSTEM</strong></div>
   <br><br>

 <ol>
 <li>
   Look up the model numbers of the FC HBA and of the FC HBA RISC controller. If
   it is not easy to access the label printed on the HBA, one way to look up
   these model numbers is as follows:
 <pre>[root@proj ]# dmesg -c &gt;/dev/null
 [root@proj ]# rmmod qla2xxx
 [root@proj ]# modprobe qla2xxx
 [root@proj ]# dmesg | grep -E 'qla2xxx .* QLogic | Found an ISP'
 qla2xxx [0000:01:00.0]-001d: Found an ISP2532 irq 16 iobase 0xffffc9000413e000.
 qla2xxx [0000:01:00.0]-00fb:164: QLogic QLE2562 - PCI-Express Dual Channel 8Gb Fibre Channel HBA.
 qla2xxx [0000:01:00.1]-001d: Found an ISP2532 irq 17 iobase 0xffffc9000417c000.
 qla2xxx [0000:01:00.1]-00fb:165: QLogic QLE2562 - PCI-Express Dual Channel 8Gb Fibre Channel HBA.</pre>
   The above information not only contains the HBA model number (QLE2562) but
   also the RISC controller ID (ISP2532).
 </li>
 <li>(Optional) Download the Linux version of the QConvergeConsoleCLI software package
   from <a href="http://driverdownloads.qlogic.com/">http://driverdownloads.qlogic.com/</a>
   and install that software package.
 </li>
 <li>
    Download the appropriate firmware for your QLogic card from
    <a href="http://driverdownloads.qlogic.com/">http://driverdownloads.qlogic.com/</a>.
    It is strongly recommended to use firmware version 5.x or higher for
    24xx/25xx adapters. More information about this subject can be found in
    the following e-mail thread: Vladislav Bolkhovitin and Artur Piechocki,
    <a href="http://sourceforge.net/mailarchive/forum.php?thread_name=4B4CD39F.6020401%40vlnb.net&amp;forum_name=scst-devel"><em>FC
    session gets closed with qla2x00t</em></a>, scst-devel mailing list, January 2010.

    <br><br>

    If no firmware image is available when the QLogic kernel module is loaded,
    the following error message will appear in the system log
    (/var/log/messages or /var/log/syslog):

 <pre>qla2xxx 0000:13:00.0: Firmware image unavailable.
 qla2xxx 0000:13:00.0: Failed to initialize adapter</pre>
 </li>

 <li>
   Copy the firmware image (.BIN) file to the /lib/firmware directory and
   rename it such that the kernel driver can find it. The file name that should
   be used for the firmware file depends on the RISC controller ID:
   <table border="1">
     <tr><th><b>ISP Model</b></th><th><b>Firmware file<br>name</b></th></tr>
     <tr><td>ISP 21XX</td><td>ql2100_fw.bin</td></tr>
     <tr><td>ISP 22XX</td><td>ql2200_fw.bin</td></tr>
     <tr><td>ISP 2300</td><td>ql2300_fw.bin</td></tr>
     <tr><td>ISP 2322</td><td>ql2322_fw.bin</td></tr>
     <tr><td>ISP 24XX</td><td>ql2400_fw.bin</td></tr>
     <tr><td>ISP 25XX</td><td>ql2500_fw.bin</td></tr>
     <tr><td>ISP 2031</td><td>ql2600_fw.bin</td></tr>
     <tr><td>ISP 27XX</td><td>ql2700_fw.bin</td></tr>
   </table>
 </li>
 <li>
   Update the firmware image in the HBA. Although the QLogic kernel driver is
   able to load the firmware from /lib/firmware, QLogic recommends to update
   the firmware image that resides in the HBA (see also Quinn Tran,
   <a href="http://sourceforge.net/p/scst/mailman/message/32801228/"><em>Re:
   [ANNOUNCE]: qla2x00t QLogic git integration into the SCST build
   tree</em></a>, scst-devel mailing list, September 5, 2014). An example:
   <pre>[root@proj ]# /opt/QLogic_Corporation/QConvergeConsoleCLI/qaucli -fc -b all /lib/firmware/ql2500_fw.bin</pre>
 </li>
 <li>Install the necessary kernel development packages. On a Debian system
 these packages can be installed as follows:
 <pre>[root@proj ]# apt-get install gcc linux-headers-`uname -r` lsscsi patch subversion</pre>
 On RHEL/CentOS/SL systems these packages can be installed as follows:
 <pre>[root@proj ]# yum install gcc kernel-devel lsscsi patch subversion</pre>
 And on SUSE systems these packages can be installed by running the following command:
 <pre>[root@proj ]# zypper install gcc kernel-devel lsscsi patch subversion</pre>
 </li>

 <li>
   Download the SCST source code. That source code can be downloaded either
   from the <a href="http://scst.sourceforge.net/downloads.html">SCST
   downloads page</a> or from the SCST Subversion source code
   repository.<br><br>

   In what follows it is assumed that the SCST trunk has been retrieved
   via Subversion. Installing a released SCST version is identical to
   installing the trunk after all downloaded SCST source code archives have
   been extracted in a single directory. The structure of that directory will
   be identical to that of the SCST trunk.

 <pre>[root@proj ]# svn co https://svn.code.sf.net/p/scst/svn/trunk scst</pre>

   After the above command finished a directory called 'scst' will have been
   created in the current directory, which is /root in this how-to.
 </li>

 <li>
   If you want to use the latest QLogic SCST target driver from the QLogic git,
   use the driver from the qla2x00t-32gbit directory. Please note that this
   driver has not yet reached the same maturity level as the driver in the
   qla2x00t directory.
 </li>

 <li id="blacklist">
 Unload the qla2xxx kernel module provided by your Linux distribution and blacklist it:
 <pre>[root@proj ]# echo blacklist qla2xxx >/etc/modprobe.d/blacklist-qla2xxx.conf
 [root@proj ]# rmmod qla2xxx</pre>
 </li>

 <li id="release">
   Select a build mode that suits your needs, e.g. optimal performance or
   debugging SCST. The default mode is debug mode. Here is how to switch to
   release mode:
 <pre>[root@proj scst ]# pwd
 /root/scst
 [root@proj scst ]# make 2release</pre>
 </li>

 <li>
   Now build the SCST kernel modules. But first verify that the link
   "/lib/modules/`uname -r`/build" points to the kernel headers of the
   currently running kernel. Build and install SCST, e.g. as follows:
 <pre>[root@proj ]# cd /root/scst
 [root@proj scst ]# BUILD_2X_MODULE=y CONFIG_SCSI_QLA_FC=y CONFIG_SCSI_QLA2XXX_TARGET=y make all install</pre>

   Verify that compilation and installation succeeded:
 	<pre>[root@proj scst]# ls -l /lib/modules/`uname -r`/extra/qla2*
 -rw-r--r--  1 root root  36756 Jun 20 18:46 qla2x00tgt.ko
 -rw-r--r--  1 root root 160192 Jun 20 18:46 qla2xxx_scst.ko
 </pre>
 </li>

 <li>
   Insert the kernel modules.<br>  The kernel modules have been installed in
   '/lib/modules/`your_kernel_version`/extra'.<br>  In addition, scst.h,
   scst_debug.h as well as Module.symvers or Modules.symvers have been copied
   to '/usr/local/include/scst'.<br> The first file contains all SCST's public
   interfaces used by target drivers. The other files allow target drivers to
   generate debug messages and support the kernel module build process.

 <pre>[root@proj scst]# ls -l /lib/modules/`uname -r`/extra
 total 232
 drwxr-xr-x  2 root root   4096 Jun 20 18:43 dev_handlers
 -rw-r--r--  1 root root  36756 Jun 20 18:46 qla2x00tgt.ko
 -rw-r--r--  1 root root 160192 Jun 20 18:46 qla2xxx_scst.ko
 -rw-r--r--  1 root root 190848 Jun 20 18:43 scst.ko

 [root@proj scst]# ls -l /lib/modules/`uname -r`/extra/dev_handlers
 total 192
 -rw-r--r--  1 root root 11757 Jun 20 18:43 scst_cdrom.ko
 -rw-r--r--  1 root root 10111 Jun 20 18:43 scst_changer.ko
 -rw-r--r--  1 root root 12420 Jun 20 18:43 scst_disk.ko
 -rw-r--r--  1 root root 12449 Jun 20 18:43 scst_modisk.ko
 -rw-r--r--  1 root root 10131 Jun 20 18:43 scst_processor.ko
 -rw-r--r--  1 root root 10081 Jun 20 18:43 scst_raid.ko
 -rw-r--r--  1 root root 12563 Jun 20 18:43 scst_tape.ko
 -rw-r--r--  1 root root 37937 Jun 20 18:43 scst_user.ko
 -rw-r--r--  1 root root 50194 Jun 20 18:43 scst_vdisk.ko</pre>

 where:
 <ul>
 <li>scst - SCST itself.</li>
 <li>scst_disk - device handler for disks (type 0).</li>
 <li>scst_tape - device handler for tapes (type 1).</li>
 <li>scst_processor - device handler for processors (type 3).</li>
 <li>scst_cdrom - device handler for CDROMs (type 5).</li>
 <li>scst_modisk - device handler for MO disks (type 7).</li>
 <li>scst_changer - device handler for medium changers (type 8).</li>
 <li>scst_raid - device handler for storage array controller (e.g. raid) (type C).</li>
 <li>scst_vdisk - device handler for virtual disks (file, device or ISO CD image)..</li>
 <li>scst_user - user space device handler.</li>
 </ul>
 <br>

   You can insert any of these kernel modules with the 'modprobe' program. As
   you can see, I've inserted all SCST kernel modules !!!
 <pre>[root@proj ]# for m in scst qla2xxx_scst qla2x00tgt scst_vdisk scst_user scst_disk ...; do modprobe $m; done</pre>

   This will result in the following dmesg output:

 <pre>scst: SCST version 2.0.0 loaded successfully (max mem for commands 16251MB, per device 6500MB)
 scst: Enabled features: TRACING
 scst: Target template qla2x00tgt registered successfully
 scst: Virtual device handler vdisk for type 0 registered successfully
 scst: Virtual device handler "scst_user" registered successfully</pre>
 </li>

 <li>
 Back up and rebuild the initial RAM disk such that the qla2xxx kernel module in
 that RAM disk will be replaced by qla2xxx_scst. How to do this depends on your
 Linux distribution. The initial RAM disk can be rebuilt e.g. as follows:
 <pre>[root@proj ]# type update-initrd >/dev/null 2>&amp;1 &amp;&amp; update-initrd -c -k `uname -r`
 [root@proj ]# type update-initramfs >/dev/null 2>&amp;1 &amp;&amp; update-initramfs -c -k `uname -r`
 [root@proj ]# if type mkinitrd >/dev/null 2>&amp;1; then
 if { rpm -q sles-release || rpm -q openSUSE-release; } >/dev/null 2>&amp;1;
 then mkinitrd; else mkinitrd -f /boot/initramfs-`uname -r`.img `uname -r`; fi; fi</pre>
 </li>

 <li>
 Now let's create our virtual device:

 <pre>[root@proj ]# dd if=/dev/zero of=/mnt/disk1 bs=1024k count=512
 512+0 records in
 512+0 records out

 [root@proj ]# ls -l /mnt/disk1
 -rw-r--r--  1 root root 536870912 Jun 23 13:27 /mnt/disk1

 [root@proj ]# file /mnt/disk1
 /mnt/disk1: data</pre>
 </li>

 <li>The next step is to install scstadmin:
   <pre>[root@proj ]# make -C scstadmin -s install</pre>
 </li>

 <li id="target-mode">
   To see the device on the initiator we have to add it in the LUNs set of our
   target.<br>  We must have a LUN with number 0 (LUs numeration must not start
   from, e.g., 1).<br><br>

   The simplest way to do that is to generate an scstadmin config file, e.g. as
   follows:

 <pre>modprobe qla2x00tgt
 find /sys/kernel/scst_tgt/targets/qla2x00t -name enabled | \
 while read f; do echo 1 >$f & done; wait
 find /sys -name issue_lip | while read f; do echo 1 >$f & done; wait
 {
 cat &lt;&lt;EOF
 HANDLER vdisk_fileio {
         DEVICE disk1 {
                 filename /mnt/disk1
         }
 }
 EOF
 for p in /sys/kernel/scst_tgt/targets/qla2x00t/*; do
 [ -d $p ] || continue
 cat &lt;&lt;EOF

 TARGET_DRIVER qla2x00t {
         TARGET $(basename $p) {
                 enabled 1

                 LUN 0 disk1
         }
 }
 EOF
 done
 } >scst.conf</pre>

 Check the generated config file. If it looks fine to you, move it to the
 default location:
 <pre>mv -i scst.conf /etc/scst.conf</pre>

 The SCST configuration in that file can be applied via scstadmin:

 <pre>[root@proj ]# scstadmin -config /etc/scst.conf

 Collecting current configuration: done.

 -> Checking configuration file 'qq' for errors.
 	-> Done, 0 warnings found.

 	-> Opening device 'disk1' using handler 'vdisk_fileio': done.
 	-> Adding device 'disk1' at LUN 0 to driver/target 'qla2x00t/25:00:00:f0:98:87:92:f3': done.
 	-> Enabling driver/target 'qla2x00t/25:00:00:f0:98:87:92:f3': done.

 	All done.</pre>


 The same can be done directly via the sysfs interface of SCST:
 <pre>
 [root@proj ]# echo "add_device disk1 filename=/mnt/disk1" >/sys/kernel/scst_tgt/handlers/vdisk_fileio/mgmt
 [root@proj ]# echo "add disk1 0" >/sys/kernel/scst_tgt/targets/qla2x00t/25:00:00:f0:98:87:92:f3/luns/mgmt
 [root@proj ]# echo "1" >/sys/kernel/scst_tgt/targets/qla2x00t/25:00:00:f0:98:87:92:f3/enabled
 </pre>
 </li>
 <li>If you want to configure LUN masking the next step is to configure
   one initiator group per initiator. To do that you need to discover the
   initiator port WWNs. One way to discover these is as follows:
   <pre>[root@proj ]# ls -d /sys/kernel/scst_tgt/targets/qla2x00t/*/sessions/*|sed 's,.*/,,' | sort -u
 10:00:00:00:c9:95:c7:1a
 10:00:00:00:c9:95:c7:1b
 21:00:00:24:ff:46:c0:84
 21:00:00:24:ff:46:c0:85
 21:00:00:24:ff:6c:ca:d8
 21:00:00:24:ff:6c:ca:d9
 21:00:00:24:ff:6c:ca:da
 21:00:00:24:ff:6c:ca:db</pre>
   More information about initiator group configuration together with an
   example can be found in the scst.conf man page.</li>
 </ol>

 <br>
 <div style="text-align: center;"><strong>INITIATOR SYSTEM</strong></div>
 <br>

 <ol>
 <li>
   A quote from the SCST README:<blockquote><em> Without loading appropriate
   device handler, corresponding device will be invisible for remote
   initiators, hence we have to add them manually.</em></blockquote>  But as
   I've already loaded the device handler (scst_vdisk) on the target, I don't
   have to perform any additional steps.
 </li>

 <li>
   After <a href="#target-mode">enabling the target mode</a> on the target, to
   see new targets and devices on the initiator you need have to trigger a
   rescan on the initiator. That is possible either by rebooting the initiator
   or by unloading and reloading the initiator kernel module.  Automatic
   discovery isn't supported by all known initiators, so you need a way to make
   SCSI subsystem on the initiator to do the new devices discovery and hence be
   able to see the new devices attached.

   Alternatively, if your initiator already connected to the target and you
   simply added new devices to it, you can try to run a manual rescan as follows:

 <pre>[root@initiator ]# echo "- - -" >/sys/class/scsi_host/hostX/scan</pre>
 where X is the host number.
 </li>

 </ol>

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	<title>
	QLogic FC Target Driver How-to for 22xx/23xx/24xx/25xx/26xx Adapters
	</title>
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	<div style="text-align: center;">
	<strong>How to Configure the FC QLogic Target Driver for
	22xx/23xx/24xx/25xx/26xx Adapters</strong></div>
	<br><br>

	<div style="text-align: center;"> <strong>TARGET SYSTEM</strong></div>
	<br><br>

	<ol>
	<li>
	Look up the model numbers of the FC HBA and of the FC HBA RISC controller. If
	it is not easy to access the label printed on the HBA, one way to look up
	these model numbers is as follows:
	<pre>[root@proj ]# dmesg -c >/dev/null
	[root@proj ]# rmmod qla2xxx
	[root@proj ]# modprobe qla2xxx
	[root@proj ]# dmesg \| grep -E 'qla2xxx .* QLogic \| Found an ISP'
	qla2xxx [0000:01:00.0]-001d: Found an ISP2532 irq 16 iobase 0xffffc9000413e000.
	qla2xxx [0000:01:00.0]-00fb:164: QLogic QLE2562 - PCI-Express Dual Channel 8Gb Fibre Channel HBA.
	qla2xxx [0000:01:00.1]-001d: Found an ISP2532 irq 17 iobase 0xffffc9000417c000.
	qla2xxx [0000:01:00.1]-00fb:165: QLogic QLE2562 - PCI-Express Dual Channel 8Gb Fibre Channel HBA.</pre>
	The above information not only contains the HBA model number (QLE2562) but
	also the RISC controller ID (ISP2532).
	</li>
	<li>(Optional) Download the Linux version of the QConvergeConsoleCLI software package
	from <a href="http://driverdownloads.qlogic.com/">http://driverdownloads.qlogic.com/</a>
	and install that software package.
	</li>
	<li>
	Download the appropriate firmware for your QLogic card from
	<a href="http://driverdownloads.qlogic.com/">http://driverdownloads.qlogic.com/</a>.
	It is strongly recommended to use firmware version 5.x or higher for
	24xx/25xx adapters. More information about this subject can be found in
	the following e-mail thread: Vladislav Bolkhovitin and Artur Piechocki,
	<a href="http://sourceforge.net/mailarchive/forum.php?thread_name=4B4CD39F.6020401%40vlnb.net&forum_name=scst-devel"><em>FC
	session gets closed with qla2x00t</em></a>, scst-devel mailing list, January 2010.

	<br><br>

	If no firmware image is available when the QLogic kernel module is loaded,
	the following error message will appear in the system log
	(/var/log/messages or /var/log/syslog):

	<pre>qla2xxx 0000:13:00.0: Firmware image unavailable.
	qla2xxx 0000:13:00.0: Failed to initialize adapter</pre>
	</li>

	<li>
	Copy the firmware image (.BIN) file to the /lib/firmware directory and
	rename it such that the kernel driver can find it. The file name that should
	be used for the firmware file depends on the RISC controller ID:
	<table border="1">
	<tr><th><b>ISP Model</b></th><th><b>Firmware file<br>name</b></th></tr>
	<tr><td>ISP 21XX</td><td>ql2100_fw.bin</td></tr>
	<tr><td>ISP 22XX</td><td>ql2200_fw.bin</td></tr>
	<tr><td>ISP 2300</td><td>ql2300_fw.bin</td></tr>
	<tr><td>ISP 2322</td><td>ql2322_fw.bin</td></tr>
	<tr><td>ISP 24XX</td><td>ql2400_fw.bin</td></tr>
	<tr><td>ISP 25XX</td><td>ql2500_fw.bin</td></tr>
	<tr><td>ISP 2031</td><td>ql2600_fw.bin</td></tr>
	<tr><td>ISP 27XX</td><td>ql2700_fw.bin</td></tr>
	</table>
	</li>
	<li>
	Update the firmware image in the HBA. Although the QLogic kernel driver is
	able to load the firmware from /lib/firmware, QLogic recommends to update
	the firmware image that resides in the HBA (see also Quinn Tran,
	<a href="http://sourceforge.net/p/scst/mailman/message/32801228/"><em>Re:
	[ANNOUNCE]: qla2x00t QLogic git integration into the SCST build
	tree</em></a>, scst-devel mailing list, September 5, 2014). An example:
	<pre>[root@proj ]# /opt/QLogic_Corporation/QConvergeConsoleCLI/qaucli -fc -b all /lib/firmware/ql2500_fw.bin</pre>
	</li>
	<li>Install the necessary kernel development packages. On a Debian system
	these packages can be installed as follows:
	<pre>[root@proj ]# apt-get install gcc linux-headers-`uname -r` lsscsi patch subversion</pre>
	On RHEL/CentOS/SL systems these packages can be installed as follows:
	<pre>[root@proj ]# yum install gcc kernel-devel lsscsi patch subversion</pre>
	And on SUSE systems these packages can be installed by running the following command:
	<pre>[root@proj ]# zypper install gcc kernel-devel lsscsi patch subversion</pre>
	</li>

	<li>
	Download the SCST source code. That source code can be downloaded either
	from the <a href="http://scst.sourceforge.net/downloads.html">SCST
	downloads page</a> or from the SCST Subversion source code
	repository.<br><br>

	In what follows it is assumed that the SCST trunk has been retrieved
	via Subversion. Installing a released SCST version is identical to
	installing the trunk after all downloaded SCST source code archives have
	been extracted in a single directory. The structure of that directory will
	be identical to that of the SCST trunk.

	<pre>[root@proj ]# svn co https://svn.code.sf.net/p/scst/svn/trunk scst</pre>

	After the above command finished a directory called 'scst' will have been
	created in the current directory, which is /root in this how-to.
	</li>

	<li>
	If you want to use the latest QLogic SCST target driver from the QLogic git,
	use the driver from the qla2x00t-32gbit directory. Please note that this
	driver has not yet reached the same maturity level as the driver in the
	qla2x00t directory.
	</li>

	<li id="blacklist">
	Unload the qla2xxx kernel module provided by your Linux distribution and blacklist it:
	<pre>[root@proj ]# echo blacklist qla2xxx >/etc/modprobe.d/blacklist-qla2xxx.conf
	[root@proj ]# rmmod qla2xxx</pre>
	</li>

	<li id="release">
	Select a build mode that suits your needs, e.g. optimal performance or
	debugging SCST. The default mode is debug mode. Here is how to switch to
	release mode:
	<pre>[root@proj scst ]# pwd
	/root/scst
	[root@proj scst ]# make 2release</pre>
	</li>

	<li>
	Now build the SCST kernel modules. But first verify that the link
	"/lib/modules/`uname -r`/build" points to the kernel headers of the
	currently running kernel. Build and install SCST, e.g. as follows:
	<pre>[root@proj ]# cd /root/scst
	[root@proj scst ]# BUILD_2X_MODULE=y CONFIG_SCSI_QLA_FC=y CONFIG_SCSI_QLA2XXX_TARGET=y make all install</pre>

	Verify that compilation and installation succeeded:
	<pre>[root@proj scst]# ls -l /lib/modules/`uname -r`/extra/qla2*
	-rw-r--r-- 1 root root 36756 Jun 20 18:46 qla2x00tgt.ko
	-rw-r--r-- 1 root root 160192 Jun 20 18:46 qla2xxx_scst.ko
	</pre>
	</li>

	<li>
	Insert the kernel modules.<br> The kernel modules have been installed in
	'/lib/modules/`your_kernel_version`/extra'.<br> In addition, scst.h,
	scst_debug.h as well as Module.symvers or Modules.symvers have been copied
	to '/usr/local/include/scst'.<br> The first file contains all SCST's public
	interfaces used by target drivers. The other files allow target drivers to
	generate debug messages and support the kernel module build process.

	<pre>[root@proj scst]# ls -l /lib/modules/`uname -r`/extra
	total 232
	drwxr-xr-x 2 root root 4096 Jun 20 18:43 dev_handlers
	-rw-r--r-- 1 root root 36756 Jun 20 18:46 qla2x00tgt.ko
	-rw-r--r-- 1 root root 160192 Jun 20 18:46 qla2xxx_scst.ko
	-rw-r--r-- 1 root root 190848 Jun 20 18:43 scst.ko

	[root@proj scst]# ls -l /lib/modules/`uname -r`/extra/dev_handlers
	total 192
	-rw-r--r-- 1 root root 11757 Jun 20 18:43 scst_cdrom.ko
	-rw-r--r-- 1 root root 10111 Jun 20 18:43 scst_changer.ko
	-rw-r--r-- 1 root root 12420 Jun 20 18:43 scst_disk.ko
	-rw-r--r-- 1 root root 12449 Jun 20 18:43 scst_modisk.ko
	-rw-r--r-- 1 root root 10131 Jun 20 18:43 scst_processor.ko
	-rw-r--r-- 1 root root 10081 Jun 20 18:43 scst_raid.ko
	-rw-r--r-- 1 root root 12563 Jun 20 18:43 scst_tape.ko
	-rw-r--r-- 1 root root 37937 Jun 20 18:43 scst_user.ko
	-rw-r--r-- 1 root root 50194 Jun 20 18:43 scst_vdisk.ko</pre>

	where:
	<ul>
	<li>scst - SCST itself.</li>
	<li>scst_disk - device handler for disks (type 0).</li>
	<li>scst_tape - device handler for tapes (type 1).</li>
	<li>scst_processor - device handler for processors (type 3).</li>
	<li>scst_cdrom - device handler for CDROMs (type 5).</li>
	<li>scst_modisk - device handler for MO disks (type 7).</li>
	<li>scst_changer - device handler for medium changers (type 8).</li>
	<li>scst_raid - device handler for storage array controller (e.g. raid) (type C).</li>
	<li>scst_vdisk - device handler for virtual disks (file, device or ISO CD image)..</li>
	<li>scst_user - user space device handler.</li>
	</ul>
	<br>

	You can insert any of these kernel modules with the 'modprobe' program. As
	you can see, I've inserted all SCST kernel modules !!!
	<pre>[root@proj ]# for m in scst qla2xxx_scst qla2x00tgt scst_vdisk scst_user scst_disk ...; do modprobe $m; done</pre>

	This will result in the following dmesg output:

	<pre>scst: SCST version 2.0.0 loaded successfully (max mem for commands 16251MB, per device 6500MB)
	scst: Enabled features: TRACING
	scst: Target template qla2x00tgt registered successfully
	scst: Virtual device handler vdisk for type 0 registered successfully
	scst: Virtual device handler "scst_user" registered successfully</pre>
	</li>

	<li>
	Back up and rebuild the initial RAM disk such that the qla2xxx kernel module in
	that RAM disk will be replaced by qla2xxx_scst. How to do this depends on your
	Linux distribution. The initial RAM disk can be rebuilt e.g. as follows:
	<pre>[root@proj ]# type update-initrd >/dev/null 2>&1 && update-initrd -c -k `uname -r`
	[root@proj ]# type update-initramfs >/dev/null 2>&1 && update-initramfs -c -k `uname -r`
	[root@proj ]# if type mkinitrd >/dev/null 2>&1; then
	if { rpm -q sles-release \|\| rpm -q openSUSE-release; } >/dev/null 2>&1;
	then mkinitrd; else mkinitrd -f /boot/initramfs-`uname -r`.img `uname -r`; fi; fi</pre>
	</li>

	<li>
	Now let's create our virtual device:

	<pre>[root@proj ]# dd if=/dev/zero of=/mnt/disk1 bs=1024k count=512
	512+0 records in
	512+0 records out

	[root@proj ]# ls -l /mnt/disk1
	-rw-r--r-- 1 root root 536870912 Jun 23 13:27 /mnt/disk1

	[root@proj ]# file /mnt/disk1
	/mnt/disk1: data</pre>
	</li>

	<li>The next step is to install scstadmin:
	<pre>[root@proj ]# make -C scstadmin -s install</pre>
	</li>

	<li id="target-mode">
	To see the device on the initiator we have to add it in the LUNs set of our
	target.<br> We must have a LUN with number 0 (LUs numeration must not start
	from, e.g., 1).<br><br>

	The simplest way to do that is to generate an scstadmin config file, e.g. as
	follows:

	<pre>modprobe qla2x00tgt
	find /sys/kernel/scst_tgt/targets/qla2x00t -name enabled \| \
	while read f; do echo 1 >$f & done; wait
	find /sys -name issue_lip \| while read f; do echo 1 >$f & done; wait
	{
	cat <<EOF
	HANDLER vdisk_fileio {
	DEVICE disk1 {
	filename /mnt/disk1
	}
	}
	EOF
	for p in /sys/kernel/scst_tgt/targets/qla2x00t/*; do
	[ -d $p ] \|\| continue
	cat <<EOF

	TARGET_DRIVER qla2x00t {
	TARGET $(basename $p) {
	enabled 1

	LUN 0 disk1
	}
	}
	EOF
	done
	} >scst.conf</pre>

	Check the generated config file. If it looks fine to you, move it to the
	default location:
	<pre>mv -i scst.conf /etc/scst.conf</pre>

	The SCST configuration in that file can be applied via scstadmin:

	<pre>[root@proj ]# scstadmin -config /etc/scst.conf

	Collecting current configuration: done.

	-> Checking configuration file 'qq' for errors.
	-> Done, 0 warnings found.

	-> Opening device 'disk1' using handler 'vdisk_fileio': done.
	-> Adding device 'disk1' at LUN 0 to driver/target 'qla2x00t/25:00:00:f0:98:87:92:f3': done.
	-> Enabling driver/target 'qla2x00t/25:00:00:f0:98:87:92:f3': done.

	All done.</pre>


	The same can be done directly via the sysfs interface of SCST:
	<pre>
	[root@proj ]# echo "add_device disk1 filename=/mnt/disk1" >/sys/kernel/scst_tgt/handlers/vdisk_fileio/mgmt
	[root@proj ]# echo "add disk1 0" >/sys/kernel/scst_tgt/targets/qla2x00t/25:00:00:f0:98:87:92:f3/luns/mgmt
	[root@proj ]# echo "1" >/sys/kernel/scst_tgt/targets/qla2x00t/25:00:00:f0:98:87:92:f3/enabled
	</pre>
	</li>
	<li>If you want to configure LUN masking the next step is to configure
	one initiator group per initiator. To do that you need to discover the
	initiator port WWNs. One way to discover these is as follows:
	<pre>[root@proj ]# ls -d /sys/kernel/scst_tgt/targets/qla2x00t//sessions/\|sed 's,.*/,,' \| sort -u
	10:00:00:00:c9:95:c7:1a
	10:00:00:00:c9:95:c7:1b
	21:00:00:24:ff:46:c0:84
	21:00:00:24:ff:46:c0:85
	21:00:00:24:ff:6c:ca:d8
	21:00:00:24:ff:6c:ca:d9
	21:00:00:24:ff:6c:ca:da
	21:00:00:24:ff:6c:ca:db</pre>
	More information about initiator group configuration together with an
	example can be found in the scst.conf man page.</li>
	</ol>

	<br>
	<div style="text-align: center;"><strong>INITIATOR SYSTEM</strong></div>
	<br>

	<ol>
	<li>
	A quote from the SCST README:<blockquote><em> Without loading appropriate
	device handler, corresponding device will be invisible for remote
	initiators, hence we have to add them manually.</em></blockquote> But as
	I've already loaded the device handler (scst_vdisk) on the target, I don't
	have to perform any additional steps.
	</li>

	<li>
	After <a href="#target-mode">enabling the target mode</a> on the target, to
	see new targets and devices on the initiator you need have to trigger a
	rescan on the initiator. That is possible either by rebooting the initiator
	or by unloading and reloading the initiator kernel module. Automatic
	discovery isn't supported by all known initiators, so you need a way to make
	SCSI subsystem on the initiator to do the new devices discovery and hence be
	able to see the new devices attached.

	Alternatively, if your initiator already connected to the target and you
	simply added new devices to it, you can try to run a manual rescan as follows:

	<pre>[root@initiator ]# echo "- - -" >/sys/class/scsi_host/hostX/scan</pre>
	where X is the host number.
	</li>

	</ol>

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