weizhouapache commented on code in PR #14386:
URL: https://github.com/apache/cloudstack/pull/14386#discussion_r4359619973
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scripts/vm/hypervisor/kvm/nasbackup.sh:
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@@ -137,6 +138,282 @@ get_linstor_uuid_from_device() {
return 1
}
+# Globals populated by parse_rbd_opts() for the disk it was last called with.
+RBD_IMAGE="" # "<pool>/<image>"
+RBD_ARGS=() # connection arguments to pass to every rbd invocation
+RBD_KEYFILE="" # temporary cephx keyfile, removed by rbd_cleanup_keyfile
+# Prefix NASBackupProvider names every chain anchor with. Snapshots carrying
it belong to this
+# tool and no other, which is what makes the stale-anchor sweep safe.
+RBD_SNAPSHOT_PREFIX="csbackup-"
+
+rbd_cleanup_keyfile() {
+ if [[ -n "$RBD_KEYFILE" ]]; then
+ rm -f "$RBD_KEYFILE"
+ RBD_KEYFILE=""
+ fi
+}
+
+# Split an RBD disk string produced by KVMPhysicalDisk.RBDStringBuilder into
the image name and
+# the connection arguments the rbd CLI needs:
+#
rbd:<pool>/<image>:mon_host=<h1>\;<h2>:auth_client_required=cephx:id=<user>:key=<secret>:...
+# ':' and ';' are backslash-escaped inside mon_host so that option splitting
stays unambiguous;
+# they are masked before the split and restored afterwards.
+parse_rbd_opts() {
+ local s="${1#rbd:}"
+ s="${s//\\:/$'\x01'}"
+ s="${s//\\;/$'\x02'}"
+ local -a parts=()
+ IFS=':' read -ra parts <<< "$s"
+
+ rbd_cleanup_keyfile
+ RBD_IMAGE="${parts[0]}"
+ RBD_ARGS=()
+
+ local p monHost="" authId="" authKey=""
+ for p in "${parts[@]:1}"; do
+ case "$p" in
+ mon_host=*) monHost="${p#mon_host=}" ;;
+ id=*) authId="${p#id=}" ;;
+ key=*) authKey="${p#key=}" ;;
+ esac
+ done
+ monHost="${monHost//$'\x01'/:}" # host\:port -> host:port
+ monHost="${monHost//$'\x02'/,}" # monitor list -> the comma-separated form
rbd -m accepts
+
+ if [[ -n "$monHost" ]]; then
+ RBD_ARGS+=(-m "$monHost")
+ fi
+ if [[ -n "$authId" ]]; then
+ RBD_ARGS+=(--id "$authId")
+ if [[ -n "$authKey" ]]; then
+ RBD_KEYFILE=$(mktemp -t csbackup-ceph.XXXXXX)
+ chmod 600 "$RBD_KEYFILE"
+ printf '%s' "$authKey" > "$RBD_KEYFILE"
+ RBD_ARGS+=(--keyfile "$RBD_KEYFILE")
+ fi
+ fi
+}
+
+# Best-effort removal of snapshot $1 from each of the remaining disk
arguments. Used both to roll
+# back a half-created anchor and to drop the previous anchor once its delta
has been exported.
+rbd_remove_snapshots() {
+ local snapName="$1"
+ shift
+ local d
+ for d in "$@"; do
+ [[ -z "$d" ]] && continue
+ parse_rbd_opts "$d"
+ if ! rbd "${RBD_ARGS[@]}" snap rm "$RBD_IMAGE@$snapName" >> "$logFile"
2>&1; then
+ log -e "cleanup: failed to remove RBD snapshot $RBD_IMAGE@$snapName
(non-fatal)"
+ fi
+ done
+ rbd_cleanup_keyfile
+}
+
+# Remove every snapshot carrying the backup prefix except $1, across the
remaining disk arguments.
+# Only snapshots this tool created are ever touched: user and CloudStack
volume snapshots do not
+# use the prefix.
+rbd_sweep_stale_anchors() {
+ local keepSnap="$1"
+ shift
+ local d stale
+ for d in "$@"; do
+ [[ -z "$d" ]] && continue
+ parse_rbd_opts "$d"
+ while read -r stale; do
+ [[ -z "$stale" || "$stale" == "$keepSnap" ]] && continue
+ if ! rbd "${RBD_ARGS[@]}" snap rm "$RBD_IMAGE@$stale" >> "$logFile"
2>&1; then
+ log -e "cleanup: failed to remove stale RBD snapshot $RBD_IMAGE@$stale
(non-fatal)"
+ fi
+ done < <(
+ rbd "${RBD_ARGS[@]}" snap ls "$RBD_IMAGE" --format json 2>>"$logFile" |
python3 -c '
+import sys, json
+try:
+ snaps = json.load(sys.stdin)
+except Exception:
+ sys.exit(0)
+for s in snaps or []:
+ name = (s or {}).get("name") or ""
+ if name.startswith(sys.argv[1]):
+ print(name)
+' "$RBD_SNAPSHOT_PREFIX" 2>/dev/null || true
+ )
+ done
+ rbd_cleanup_keyfile
+}
+
+rbd_snapshot_exists() {
+ local snapName="$1"
+ rbd "${RBD_ARGS[@]}" snap ls "$RBD_IMAGE" --format json 2>>"$logFile" |
python3 -c '
+import sys, json
+try:
+ snaps = json.load(sys.stdin)
+except Exception:
+ sys.exit(1)
+sys.exit(0 if any((s or {}).get("name") == sys.argv[1] for s in snaps or [])
else 1)
+' "$snapName"
+}
+
+# Incremental backup of Ceph/RBD volumes.
+#
+# RBD images are raw, so they have nowhere to persist a QEMU dirty bitmap and
cannot take part in
+# the libvirt-checkpoint scheme backup_running_vm uses. Ceph provides the
equivalent natively: an
+# `rbd snap` per cycle as the anchor, and `rbd export-diff --from-snap` to
stream out exactly the
+# extents that changed between two anchors (computed inside Ceph from the
image object-map).
+#
+# Because the snapshot lives in Ceph rather than in the QEMU process, this
works identically for
+# running and stopped VMs, and survives a live migration of the VM between
hosts.
+#
+# Only the newest anchor is kept on each image: once this run's delta is
exported, the parent
+# snapshot is removed. A full additionally sweeps every other snapshot
carrying the backup prefix,
+# so anchors abandoned by a deleted chain, an unassigned offering or a restore
cannot accumulate.
+backup_rbd_vm() {
+ if [[ -z "$DISK_PATHS" ]]; then
+ echo "RBD backup mode requires the volume paths (-d|--diskpaths)"
+ exit 1
+ fi
+ if [[ -z "$BITMAP_NEW" ]]; then
+ echo "RBD backup mode requires --bitmap-new (the snapshot to create)"
+ exit 1
+ fi
+
+ local effective_mode="$MODE"
+ case "$effective_mode" in
+ full|incremental)
+ ;;
+ *)
+ echo "Mode $effective_mode is not supported by the rbd method"
+ cleanup
+ exit 1
+ ;;
+ esac
+ local -a disks=()
+ IFS=',' read -ra disks <<< "$DISK_PATHS"
+
+ local d
+ for d in "${disks[@]}"; do
+ if [[ "$d" != rbd:* ]]; then
+ echo "RBD backup mode was requested but disk $d is not an RBD volume"
+ exit 1
+ fi
+ done
+
+ # The parent anchor must still be present on EVERY disk. A volume migration
or an out-of-band
+ # snapshot purge can drop it; fall back to a full rather than letting
export-diff fail. Checked
+ # before anything is mounted or created so the fallback costs nothing.
+ if [[ "$effective_mode" == "incremental" ]]; then
+ for d in "${disks[@]}"; do
+ parse_rbd_opts "$d"
+ if ! rbd_snapshot_exists "$BITMAP_PARENT"; then
+ log -e "rbd incremental: parent snapshot $BITMAP_PARENT missing on
$RBD_IMAGE — falling back to full"
+ echo "INCREMENTAL_FALLBACK=true"
+ effective_mode="full"
+ break
+ fi
+ done
+ rbd_cleanup_keyfile
+ fi
+
+ mount_operation
+ mkdir -p "$dest" || { echo "Failed to create backup directory $dest"; exit
1; }
+
+ # Freezing the guest filesystems makes the snapshot set
filesystem-consistent instead of merely
+ # crash-consistent. Only possible while the VM runs and its guest agent
answers.
+ local thaw=0
+ local vm_state
+ vm_state=$(virsh -c qemu:///system domstate "$VM" 2>/dev/null || true)
+ if [[ ${QUIESCE} == "true" && "$vm_state" == "running" ]]; then
+ if virsh -c qemu:///system qemu-agent-command "$VM"
'{"execute":"guest-fsfreeze-freeze"}' > /dev/null 2>/dev/null; then
+ thaw=1
+ fi
+ fi
+
+ # Create this cycle's anchor on every disk back to back, so the set is as
close to a single
+ # point in time for the VM as a whole as Ceph allows.
+ local -a snapped=()
+ local snap_failed=0
+ for d in "${disks[@]}"; do
Review Comment:
:+1:
updated, if thaw is 0 , pause and resume
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