~mdw / distorted-backup / blame
| Commit | Line | Data |
|---|---|---|
| 99248ed2 MW |
1 | #! /bin/sh |
| 2 | ### | |
| 3 | ### Establish snapshots of LVM logical volumes | |
| 4 | ### | |
| 5 | ### (c) 2011 Mark Wooding | |
| 6 | ### | |
| 7 | ||
| 8 | ###----- Licensing notice --------------------------------------------------- | |
| 9 | ### | |
| 10 | ### This program is free software; you can redistribute it and/or modify | |
| 11 | ### it under the terms of the GNU General Public License as published by | |
| 12 | ### the Free Software Foundation; either version 2 of the License, or | |
| 13 | ### (at your option) any later version. | |
| 14 | ### | |
| 15 | ### This program is distributed in the hope that it will be useful, | |
| 16 | ### but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 17 | ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 18 | ### GNU General Public License for more details. | |
| 19 | ### | |
| 20 | ### You should have received a copy of the GNU General Public License | |
| 21 | ### along with this program; if not, write to the Free Software Foundation, | |
| 22 | ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
| 23 | ||
| 24 | set -e | |
| 25 | quis=${0##*/} | |
| 26 | ||
| 27 | ###-------------------------------------------------------------------------- | |
| 28 | ### Parse the command line. | |
| 29 | ||
| 30 | ## Provide help or version information. | |
| 31 | usage="usage: $quis DEVICE [KEY=VALUE ...]" | |
| 32 | version="$quis, version 1.0.0" | |
| 33 | case "$#,$1" in | |
| 34 | 0,*) echo >&2 "$usage"; exit 1 ;; | |
| 35 | *,-v | *,--version) echo "$version"; exit ;; | |
| 36 | *,-h | *,--help) | |
| 37 | cat <<EOF | |
| 38 | $version | |
| 39 | $usage | |
| 40 | ||
| 41 | Option keys: | |
| 42 | op=OPERATION \`snap' to create snapshot, or \`unsnap' to remove. | |
| 43 | snapsz=SIZE Size to reserve for snapshot storage. | |
| 44 | tag=TAG Disambiguation tag to append to logical volume name. | |
| 45 | EOF | |
| 46 | exit | |
| 47 | ;; | |
| 48 | esac | |
| 49 | ||
| 50 | ## Scan the option keys. | |
| 51 | dev=$1; shift | |
| 52 | Oop=snap Otag=snap Osnapsz=100M | |
| 53 | win=t | |
| 54 | for i in "$@"; do | |
| 55 | case "$i" in | |
| 56 | ?*=*) ;; | |
| 57 | *) echo >&2 "$quis: malformed option \`$i'"; exit 1 ;; | |
| 58 | esac | |
| 59 | k=${i%%=*} v=${i#*=} | |
| 60 | case "$k" in *.lvm) k=${k%.lvm} ;; ?*.?*) continue ;; esac | |
| 61 | case "$k" in | |
| 62 | op | tag | snapsz) eval "O$k=\$v" ;; | |
| 63 | *) echo >&2 "$quis: unknown option \`$k'"; win=nil ;; | |
| 64 | esac | |
| 65 | done | |
| 66 | case $win in nil) exit 1 ;; esac | |
| 67 | ||
| 68 | ## Check the device name. | |
| 69 | case "$dev" in | |
| 70 | ?*/?*) ;; *) echo >&2 "$quis: device \`$dev' should be VG/LV"; exit 1 ;; | |
| 71 | esac | |
| 72 | vg=${dev%%/*} lv=${dev#*/} | |
| 73 | ||
| 74 | ###-------------------------------------------------------------------------- | |
| 75 | ### Take or remove the snapshot. | |
| 76 | ||
| 77 | case "$Oop" in | |
| 78 | ||
| 79 | snap) | |
| 80 | case "$Osnapsz" in | |
| 81 | *%*) szarg="extents" ;; | |
| 82 | *) szarg="size" ;; | |
| 83 | esac | |
| 84 | lvcreate >/dev/null --snapshot \ | |
| 85 | --$szarg="$Osnapsz" \ | |
| 86 | --name="$lv.$Otag" \ | |
| 87 | "$vg/$lv" | |
| 88 | echo "$vg/$lv.$Otag" | |
| 89 | ;; | |
| 90 | ||
| 91 | unsnap) | |
| 92 | ## LVM snapshot removal is full of awful bugs, mostly to do with races | |
| 93 | ## with udev. We have a handy script which does the necessary. May it | |
| 94 | ## not be needed for long. | |
| 95 | lvm-rmsnap >/dev/null "$vg/$lv.$Otag" | |
| 96 | ;; | |
| 97 | ||
| 98 | *) | |
| 99 | echo >&2 "$quis: unknown operation \`$Oop'" | |
| 100 | exit 1 | |
| 101 | ;; | |
| 102 | ||
| 103 | esac | |
| 104 | ||
| 105 | ###----- That's all, folks -------------------------------------------------- |