| '\" t |
| .\" |
| .\" CDDL HEADER START |
| .\" |
| .\" The contents of this file are subject to the terms of the |
| .\" Common Development and Distribution License (the "License"). |
| .\" You may not use this file except in compliance with the License. |
| .\" |
| .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
| .\" or http://www.opensolaris.org/os/licensing. |
| .\" See the License for the specific language governing permissions |
| .\" and limitations under the License. |
| .\" |
| .\" When distributing Covered Code, include this CDDL HEADER in each |
| .\" file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
| .\" If applicable, add the following below this CDDL HEADER, with the |
| .\" fields enclosed by brackets "[]" replaced with your own identifying |
| .\" information: Portions Copyright [yyyy] [name of copyright owner] |
| .\" |
| .\" CDDL HEADER END |
| .\" |
| .\" |
| .\" Copyright 2013 Darik Horn <dajhorn@vanadac.com>. All rights reserved. |
| .\" |
| .TH zhack 1 "2013 MAR 16" "ZFS on Linux" "User Commands" |
| |
| .SH NAME |
| zhack \- libzpool debugging tool |
| .SH DESCRIPTION |
| This utility pokes configuration changes directly into a ZFS pool, |
| which is dangerous and can cause data corruption. |
| .SH SYNOPSIS |
| .LP |
| .BI "zhack [\-c " "cachefile" "] [\-d " "dir" "] <" "subcommand" "> [" "arguments" "]" |
| .SH OPTIONS |
| .HP |
| .BI "\-c" " cachefile" |
| .IP |
| Read the \fIpool\fR configuration from the \fIcachefile\fR, which is |
| /etc/zfs/zpool.cache by default. |
| .HP |
| .BI "\-d" " dir" |
| .IP |
| Search for \fIpool\fR members in the \fIdir\fR path. Can be specified |
| more than once. |
| .SH SUBCOMMANDS |
| .LP |
| .BI "feature stat " "pool" |
| .IP |
| List feature flags. |
| .LP |
| .BI "feature enable [\-d " "description" "] [\-r] " "pool guid" |
| .IP |
| Add a new feature to \fIpool\fR that is uniquely identified by |
| \fIguid\fR, which is specified in the same form as a zfs(8) user |
| property. |
| .IP |
| The \fIdescription\fR is a short human readable explanation of the new |
| feature. |
| .IP |
| The \fB\-r\fR switch indicates that \fIpool\fR can be safely opened |
| in read-only mode by a system that does not have the \fIguid\fR |
| feature. |
| .LP |
| .BI "feature ref [\-d|\-m] " "pool guid" |
| .IP |
| Increment the reference count of the \fIguid\fR feature in \fIpool\fR. |
| .IP |
| The \fB\-d\fR switch decrements the reference count of the \fIguid\fR |
| feature in \fIpool\fR. |
| .IP |
| The \fB\-m\fR switch indicates that the \fIguid\fR feature is now |
| required to read the pool MOS. |
| .SH EXAMPLES |
| .LP |
| .nf |
| # zhack feature stat tank |
| |
| for_read_obj: |
| org.illumos:lz4_compress = 0 |
| for_write_obj: |
| com.delphix:async_destroy = 0 |
| com.delphix:empty_bpobj = 0 |
| descriptions_obj: |
| com.delphix:async_destroy = Destroy filesystems asynchronously. |
| com.delphix:empty_bpobj = Snapshots use less space. |
| org.illumos:lz4_compress = LZ4 compression algorithm support. |
| .LP |
| # zhack feature enable -d 'Predict future disk failures.' \\ |
| tank com.example:clairvoyance |
| .LP |
| # zhack feature ref tank com.example:clairvoyance |
| .SH AUTHORS |
| This man page was written by Darik Horn <dajhorn@vanadac.com>. |
| .SH SEE ALSO |
| .BR zfs (8), |
| .BR zpool-features (5), |
| .BR ztest (1) |