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
|
#! /bin/sh
#
# Copyright © 2012, 2014, 2015, 2017 Richard Kettlewell.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
set -e
SNAPS=/var/lib/rsbackup/snapshots
DIVISOR=5
# By default LVM whines about any FDs it doesn't know about
export LVM_SUPPRESS_FD_WARNINGS=1
x() {
fatal_errors=true
case "$1" in
+e )
shift
fatal_errors=false
;;
esac
echo "HOOK: EXEC:" "$@" >&2
if $fatal_errors; then
"$@"
else
set +e
"$@"
status=$?
set -e
fi
}
while [ $# -gt 0 ]; do
case "$1" in
--help | -h )
cat <<EOF
Usage:
rsbackup-snapshot-hook [OPTIONS]
Options:
--snaps, -s PATH Snapshot directory path (${SNAPS})
--divisor, -d DIVISOR How much smaller snapshot can be (${DIVISOR})
--help, -h Display usage message
--version, -V Display version string
This script is intended to be run as an rsbackup pre/post-backup hook,
not interactively.
EOF
exit 0
;;
-s | --snaps )
shift
SNAPS="$1"
shift
;;
-d | --divisor )
shift
DIVISOR="$1"
shift
;;
-V | --version )
echo "rsbackup-snapshot-hook _version_"
exit 0
;;
* )
echo "ERROR: unknown option '$1'" >&2
exit 1
;;
esac
done
# The path where the snapshot will be mounted
snap=$SNAPS/$RSBACKUP_VOLUME
# How to execute commands on the host
case $RSBACKUP_SSH_TARGET in
localhost )
remote=""
;;
* )
remote="ssh $RSBACKUP_SSH_TARGET"
;;
esac
# Only use snapshots if configured to do so
if ${RSBACKUP_ACT:-false} && $remote test -e $snap; then
# Identify the device name
devname=$($remote df ${RSBACKUP_VOLUME_PATH}|awk '/^\// { print $1}')
# Canonicalize the device name
dev=""
for alias in $(x $remote udevadm info -rqsymlink -n "$devname"); do
case "$alias" in
/dev/mapper/* )
dev="${alias}"
break
;;
esac
done
if [ "${dev}" = "" ]; then
echo >&2 "ERROR: cannot parse device name $devname"
exit 1
fi
lv=${dev#*-}
snaplv=${lv}.snap
snapdev=${dev%-*}-${snaplv}
case ${RSBACKUP_HOOK} in
pre-backup-hook )
# Tidy up any leftovers
if $remote [ -e $snapdev ]; then
x $remote umount $snap >&2 || true
x $remote lvremove --force $snapdev >&2 || true
fi
# Find out the size of the source volume
lvsz=$($remote lvdisplay $dev | awk '/Current LE/ { print $3 }')
lvname=$($remote lvdisplay $dev | awk '/LV Path/ { print $3 }')
if [ "$lvname" = "" ]; then
lvname=$($remote lvdisplay $dev | awk '/LV Name/ { print $3 }')
fi
snaplvsz=$(($lvsz / $DIVISOR))
# Create and mount the snapshot
x $remote lvcreate --extents $snaplvsz --name $snaplv --snapshot $lvname >&2
# Snapshots may need fscking before mounting
# fsck status is a bitmap; 1 means that errors were corrected.
# All the other nonzero bits are fatal.
x +e $remote fsck -a $snapdev >&2
case $status in
0 | 1 )
;;
* )
x $remote lvremove --force $snapdev >&2
exit $status
;;
esac
x $remote mount -o ro $snapdev $snap >&2
# Backup from the snapshot, not the master
echo $snap
;;
post-backup-hook )
# Tidy up
x $remote umount $snap >&2
x $remote lvremove --force $snapdev >&2
;;
esac
fi
|
