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Makefile.am: Stupid workaround for new Automake pettiness.
[distorted-backup] / snap.lvm
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1#! /bin/sh
2###
3### Establish snapshots of LVM logical volumes
4###
5### (c) 2011 Mark Wooding
6###
7
8###----- Licensing notice ---------------------------------------------------
9###
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10### This file is part of the distorted.org.uk backup suite.
11###
12### distorted-backup is free software; you can redistribute it and/or modify
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13### it under the terms of the GNU General Public License as published by
14### the Free Software Foundation; either version 2 of the License, or
15### (at your option) any later version.
16###
13678d88 17### distorted-backup is distributed in the hope that it will be useful,
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18### but WITHOUT ANY WARRANTY; without even the implied warranty of
19### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20### GNU General Public License for more details.
21###
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22### You should have received a copy of the GNU General Public License along
23### with distorted-backup; if not, write to the Free Software Foundation,
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24### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25
26set -e
27quis=${0##*/}
28
29###--------------------------------------------------------------------------
30### Parse the command line.
31
32## Provide help or version information.
33usage="usage: $quis DEVICE [KEY=VALUE ...]"
34version="$quis, version 1.0.0"
35case "$#,$1" in
36 0,*) echo >&2 "$usage"; exit 1 ;;
37 *,-v | *,--version) echo "$version"; exit ;;
38 *,-h | *,--help)
39 cat <<EOF
40$version
41$usage
42
43Option keys:
44 op=OPERATION \`snap' to create snapshot, or \`unsnap' to remove.
45 snapsz=SIZE Size to reserve for snapshot storage.
46 tag=TAG Disambiguation tag to append to logical volume name.
47EOF
48 exit
49 ;;
50esac
51
52## Scan the option keys.
53dev=$1; shift
54Oop=snap Otag=snap Osnapsz=100M
55win=t
56for i in "$@"; do
57 case "$i" in
58 ?*=*) ;;
59 *) echo >&2 "$quis: malformed option \`$i'"; exit 1 ;;
60 esac
61 k=${i%%=*} v=${i#*=}
62 case "$k" in *.lvm) k=${k%.lvm} ;; ?*.?*) continue ;; esac
63 case "$k" in
64 op | tag | snapsz) eval "O$k=\$v" ;;
65 *) echo >&2 "$quis: unknown option \`$k'"; win=nil ;;
66 esac
67done
68case $win in nil) exit 1 ;; esac
69
70## Check the device name.
71case "$dev" in
72 ?*/?*) ;; *) echo >&2 "$quis: device \`$dev' should be VG/LV"; exit 1 ;;
73esac
74vg=${dev%%/*} lv=${dev#*/}
75
76###--------------------------------------------------------------------------
77### Take or remove the snapshot.
78
79case "$Oop" in
80
81 snap)
82 case "$Osnapsz" in
83 *%*) szarg="extents" ;;
84 *) szarg="size" ;;
85 esac
86 lvcreate >/dev/null --snapshot \
87 --$szarg="$Osnapsz" \
88 --name="$lv.$Otag" \
89 "$vg/$lv"
90 echo "$vg/$lv.$Otag"
91 ;;
92
93 unsnap)
94 ## LVM snapshot removal is full of awful bugs, mostly to do with races
95 ## with udev. We have a handy script which does the necessary. May it
96 ## not be needed for long.
97 lvm-rmsnap >/dev/null "$vg/$lv.$Otag"
98 ;;
99
100 *)
101 echo >&2 "$quis: unknown operation \`$Oop'"
102 exit 1
103 ;;
104
105esac
106
107###----- That's all, folks --------------------------------------------------