@ -33,11 +33,13 @@ Options:
-d DOMAIN specify domain name ( you can specify multiple -d options)
-s SNAPSHOT specify snapshot name
-b batch mode ( pause all domains, take snapshots, then resume all domains)
-k N keep at most N snapshots per domain ( used with 'prune' action)
Actions:
snapshot take a snapshot of the specified domain( s)
revert revert to a snapshot of the specified domain( s)
list list snapshots of the specified domain( s) ( or all domains if none specified)
prune prune old snapshots of the specified domain( s) according to retention policy
Examples:
Take a crash-consistent snapshot of domain 'vm1' named 'backup1' :
@ -54,6 +56,9 @@ Examples:
List snapshots of all domains:
${ 0 ##*/ } list
Prune snapshots of all domains, keeping at most 5 snapshots:
${ 0 ##*/ } prune -k 5
EOF
}
@ -66,6 +71,7 @@ function init_global_variables () {
action = ""
batch = 0
live = 0
keep = 0
# Cache for domain parameters to avoid redundant calls to the zfs command
declare -gA domain_params_cache = ( )
@ -83,7 +89,7 @@ function parse_args () {
OPTIND = 1 # Reset in case getopts has been used previously in the shell.
while getopts "h?blvd:s:" opt; do
while getopts "h?blvd:s:k: " opt; do
case " $opt " in
h| \? )
show_help
@ -99,6 +105,8 @@ function parse_args () {
; ;
l) live = 1
; ;
k) keep = " $OPTARG "
; ;
*) show_help >& 2
exit 1
; ;
@ -114,6 +122,11 @@ function parse_args () {
should_exit = 1
fi
if [ ${# domains [@] } -eq 0 ] ; then
# Get all domains
mapfile -t domains < <( virsh list --all --name | grep -v '^$' )
fi
case " $action " in
snapshot)
if [ ${# domains [@] } -eq 0 ] || [ -z " $snapshot_name " ] ; then
@ -139,6 +152,12 @@ function parse_args () {
; ;
list)
; ;
prune)
if [ " $keep " -le 0 ] ; then
echo "Error: The -k option with a positive integer value must be specified for the 'prune' action."
should_exit = 1
fi
; ;
*)
echo " Error: Unsupported action ' $action '. "
should_exit = 1
@ -164,7 +183,10 @@ function domain_exists () {
function domain_checks ( ) {
local action = " $1 "
local domain = " $2 "
local snapshot_name = " $3 "
local snapshot_name
if [ " $action " = = "snapshot" ] || [ " $action " = = "revert" ] ; then
snapshot_name = " $3 "
fi
local error = 0
local state = ""
@ -194,8 +216,6 @@ function domain_checks () {
if [ -z " $zfs_mountpoint " ] || [ [ ! " $zfs_mountpoint " = ~ ^/ ] ] ; then
error " $domain : Wrong ZFS mountpoint for dataset ' $zfs_dataset ': ' $zfs_mountpoint '. " ; error = 1
# elif [ ! -d "$zfs_mountpoint" ]; then
# error "$domain: ZFS mountpoint '$zfs_mountpoint' does not exist." ; error=1
fi
state = $( domain_state " $domain " )
@ -205,6 +225,7 @@ function domain_checks () {
domain_params_cache[ " $domain /dataset " ] = " ${ zfs_dataset } "
domain_params_cache[ " $domain /mountpoint " ] = " ${ zfs_mountpoint } "
domain_params_cache[ " $domain /zvols " ] = " ${ zfs_zvols [*] } "
domain_params_cache[ " $domain /snapshots " ] = " ${ zfs_dataset_snapshots [*] } "
case " $action " in
snapshot)
@ -251,7 +272,15 @@ function domain_checks () {
fi
done
; ;
list)
; ;
prune)
if [ ${# zfs_dataset_snapshots [@] } -le " $keep " ] ; then
log_verbose " $domain : No snapshots to prune (total: ${# zfs_dataset_snapshots [@] } , keep: $keep ). "
fi
; ;
*)
# Should not reach here due to prior validation
error " $domain : Unknown action ' $action '. "
; ;
esac
@ -381,13 +410,20 @@ function resume_all_domains () {
# Performs pre-flight checks for all specified domains according to the action.
function preflight_checks ( ) {
local action = " $1 " ; shift
local snapshot_name = " $1 " ; shift
local snapshot_name
if [ " $action " = = "snapshot" ] || [ " $action " = = "revert" ] ; then
snapshot_name = " $1 " ; shift
fi
local error = 0
local domains = ( " $@ " )
for domain in " ${ domains [@] } " ; do
log_verbose " $domain : Performing domain pre-flight checks for $action ... "
if ! domain_checks " $action " " $domain " " $snapshot_name " ; then
local -a domain_checks_args = ( " $action " " $domain " )
if [ " $action " = = "snapshot" ] || [ " $action " = = "revert" ] ; then
domain_checks_args += ( " $snapshot_name " )
fi
if ! domain_checks " ${ domain_checks_args [@] } " ; then
error = 1
fi
done
@ -395,6 +431,7 @@ function preflight_checks () {
return $error
}
# Removes the save file for the specified domain.
function remove_save_file ( ) {
local domain = " $1 "
@ -510,18 +547,35 @@ function revert_snapshots () {
# Lists snapshots for all specified domains.
function list_snapshots ( ) {
local domains = ( " $@ " )
local zfs_datasets
local zfs_dataset
local domain
local snapshot
for domain in " ${ domains [@] } " ; do
zfs_datasets = ( $( get_zfs_datasets_from_domain " $domain " ) )
if [ ${# zfs_datasets [@] } -ne 1 ] ; then
error " $domain : Wrong number of ZFS datasets ( ${# zfs_datasets [@] } ) found. " ; return 1
fi
zfs_dataset = " ${ zfs_datasets [0] :- } "
echo " Snapshots for domain ' $domain ': "
get_zfs_snapshots_from_dataset " $zfs_dataset " | sed 's/^/ - /'
for snapshot in ${ domain_params_cache [ " $domain /snapshots " ] } ; do
echo " - $snapshot "
done
done
}
# Prunes old snapshots for all specified domains according to the retention policy.
function prune_snapshots ( ) {
local domains = ( " $@ " )
local dataset
local snapshots
local domain
for domain in " ${ domains [@] } " ; do
snapshots = ( ${ domain_params_cache [ " $domain /snapshots " ] } )
dataset = " ${ domain_params_cache [ " $domain /dataset " ] } "
if [ " ${# snapshots [@] } " -le " $keep " ] ; then
continue
fi
local first_to_delete_idx = $(( ${# snapshots [@] } - keep - 1 ))
local first_to_delete = " ${ snapshots [ $first_to_delete_idx ] } "
if [ -z " $first_to_delete " ] ; then
continue
fi
zfs destroy -r " ${ dataset } @% ${ first_to_delete } "
done
}
