snapshot, is this normal?

[Jae Lee]

i've just took a snapshot backup and my VM stopped responding:

INFO: starting new backup job: vzdump 101 --remove 0 --mode snapshot --compress lzo --storage hit2tb --node server1
INFO: Starting Backup of VM 101 (qemu)
INFO: status = running
INFO: mode failure - unable to detect lvm volume group
INFO: trying 'suspend' mode instead
INFO: backup mode: suspend
INFO: ionice priority: 7
INFO: suspend vm
INFO: creating archive '/storage/hit2tb/dump/vzdump-qemu-101-2012_10_25-22_25_46.tar.lzo'
INFO: adding '/storage/hit2tb/dump/vzdump-qemu-101-2012_10_25-22_25_46.tmp/qemu-server.conf' to archive ('qemu-server.conf')
INFO: adding '/var/lib/vz/images/101/vm-101-disk-1.raw' to archive ('vm-disk-ide0.raw')

and it's been hanging there for over 30 minutes.

while taking snapshot, is it normal that your server becomes unresponsive?

i'm on 2.1 btw.

 

[Jae Lee]

okay so backup just took a long time, 50 mins and now its done and everything is back to normal.
i'm surprised though, that it knocked out my VM (all sites down) during this backup process.

 

[tom]

seem you do not have the right LVM setup (see your log - mode failure).

post the output of:
- pveversion -v
- pveperf
- full backup log

and give details about your hardware and your backup target (/storage/hit2tb)

you can also limit the backup speed to prevent overload on your server.

 

[Jae Lee]

root@server1:~# pveversion -v
pve-manager: 2.1-1 (pve-manager/2.1/f9b0f63a)
running kernel: 2.6.32-11-pve
proxmox-ve-2.6.32: 2.0-66
pve-kernel-2.6.32-11-pve: 2.6.32-66
lvm2: 2.02.95-1pve2
clvm: 2.02.95-1pve2
corosync-pve: 1.4.3-1
openais-pve: 1.1.4-2
libqb: 0.10.1-2
redhat-cluster-pve: 3.1.8-3
resource-agents-pve: 3.9.2-3
fence-agents-pve: 3.1.7-2
pve-cluster: 1.0-26
qemu-server: 2.0-39
pve-firmware: 1.0-15
libpve-common-perl: 1.0-27
libpve-access-control: 1.0-21
libpve-storage-perl: 2.0-18
vncterm: 1.0-2
vzctl: 3.0.30-2pve5
vzprocps: 2.0.11-2
vzquota: 3.0.12-3
pve-qemu-kvm: 1.0-9
ksm-control-daemon: 1.1-1

root@server1:~# pveperf
CPU BOGOMIPS: 166380.72
REGEX/SECOND: 458203
HD SIZE: 54.88 GB (/dev/mapper/pve-root)
BUFFERED READS: 191.69 MB/sec
AVERAGE SEEK TIME: 0.19 ms
FSYNCS/SECOND: 2369.09
DNS EXT: 96.59 ms
DNS INT: 215.68 ms

INFO: starting new backup job: vzdump 101 --remove 0 --mode snapshot --compress lzo --storage hit2tb --node server1
INFO: Starting Backup of VM 101 (qemu)
INFO: status = running
INFO: mode failure - unable to detect lvm volume group
INFO: trying 'suspend' mode instead
INFO: backup mode: suspend
INFO: ionice priority: 7
INFO: suspend vm
INFO: creating archive '/storage/hit2tb/dump/vzdump-qemu-101-2012_10_25-22_25_46.tar.lzo'
INFO: adding '/storage/hit2tb/dump/vzdump-qemu-101-2012_10_25-22_25_46.tmp/qemu-server.conf' to archive ('qemu-server.conf')
INFO: adding '/var/lib/vz/images/101/vm-101-disk-1.raw' to archive ('vm-disk-ide0.raw')
INFO: adding '/storage/hit2tb/images/101/vm-101-disk-1.raw' to archive ('vm-disk-ide1.raw')
INFO: Total bytes written: 322122550272 (209.55 MiB/s)
INFO: archive file size: 27.00GB
INFO: resume vm
INFO: vm is online again after 2932 seconds
INFO: Finished Backup of VM 101 (00:48:52)
INFO: Backup job finished successfully
TASK OK

/storage/hit2tb is an extra HDD i added specifically for dealing with backups.

 

[dietmar]

/storage/hit2tb is an extra HDD i added specifically for dealing with backups.

I guess there is no LVM on this HD, so it is impossible to use LVM snapshots.

 

[rcd]

I guess there is no LVM on this HD, so it is impossible to use LVM snapshots.

The vzdump(1) man page says:

Proxmox VE live backup provides snapshot-like semantics on any storage type. It does not require that the
underlying storage supports snapshots. Also please note that since the backups are done via a background
Qemu process, a stopped VM will appear as running for a short amount of time while the VM disks are being
read by Qemu. However the VM itself is not booted, only its disk(s) are read.

I'm just wondering how to understand this, as it conflicts with the above statement, and also with my own observations. No LVM - no snapshot. So how should we understand the man page?

And somewhat related .... is it possible to use compression with snapshots and maintain the no-downtime? (vzdump --mode snapshot --compress or --pigz)

 

[fabian]

The vzdump(1) man page says:



I'm just wondering how to understand this, as it conflicts with the above statement, and also with my own observations. No LVM - no snapshot. So how should we understand the man page?

And somewhat related .... is it possible to use compression with snapshots and maintain the no-downtime? (vzdump --mode snapshot --compress or --pigz)

please don't resurrect ancient threads. "snapshot" backup mode does not use storage-level snapshots for VMs (for CTs it does). compression happens on the output of the backup process, it does not matter which mode was used.