aboutsummaryrefslogtreecommitdiffstats
path: root/man/man1/zhack.1
blob: 937f1e9168c29d56af6b7126d2472e68a9c6f949 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
.\"
.\" 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 https://opensource.org/licenses/CDDL-1.0.
.\" 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.
.\"
.\" lint-ok: WARNING: sections out of conventional order: Sh SYNOPSIS
.\"
.Dd May 26, 2021
.Dt ZHACK 1
.Os
.
.Sh NAME
.Nm zhack
.Nd 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
.Bl -tag -width Ds
.It Xo
.Nm zhack
.Cm feature stat
.Ar pool
.Xc
List feature flags.
.
.It Xo
.Nm zhack
.Cm feature enable
.Op Fl d Ar description
.Op Fl r
.Ar pool
.Ar guid
.Xc
Add a new feature to
.Ar pool
that is uniquely identified by
.Ar guid ,
which is specified in the same form as a
.Xr zfs 8
user property.
.Pp
The
.Ar description
is a short human readable explanation of the new feature.
.Pp
The
.Fl r
flag indicates that
.Ar pool
can be safely opened in read-only mode by a system that does not understand the
.Ar guid
feature.
.
.It Xo
.Nm zhack
.Cm feature ref
.Op Fl d Ns | Ns Fl m
.Ar pool
.Ar guid
.Xc
Increment the reference count of the
.Ar guid
feature in
.Ar pool .
.Pp
The
.Fl d
flag decrements the reference count of the
.Ar guid
feature in
.Ar pool
instead.
.Pp
The
.Fl m
flag indicates that the
.Ar guid
feature is now required to read the pool MOS.
.
.It Xo
.Nm zhack
.Cm label repair
.Op Fl cu
.Ar device
.Xc
Repair labels of a specified
.Ar device
according to options.
.Pp
Flags may be combined to do their functions simultaneously.
.
.Pp
The
.Fl c
flag repairs corrupted label checksums
.
.Pp
The
.Fl u
flag restores the label on a detached device
.Pp
Example:
.Nm zhack Cm label repair Fl cu Ar device
  Fix checksums and undetach a device
.
.El
.
.Sh GLOBAL OPTIONS
The following can be passed to all
.Nm
invocations before any subcommand:
.Bl -tag -width "-d dir"
.It Fl c Ar cachefile
Read
.Ar pool
configuration from the
.Ar cachefile ,
which is
.Pa /etc/zfs/zpool.cache
by default.
.It Fl d Ar dir
Search for
.Ar pool
members in
.Ar dir .
Can be specified more than once.
.El
.
.Sh EXAMPLES
.Bd -literal
.No # Nm zhack Cm feature stat Ar 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.

.No # Nm zhack Cm feature enable Fl d No 'Predict future disk failures.' Ar tank com.example:clairvoyance
.No # Nm zhack Cm feature ref Ar tank com.example:clairvoyance
.Ed
.
.Sh SEE ALSO
.Xr ztest 1 ,
.Xr zpool-features 7 ,
.Xr zfs 8