[SOLVED] LXC Backup randomly hangs at suspend


Proxmox Staff Member
Staff member
Jan 7, 2016
the vzdump "snapshot" mode for Qemu is completely different from the vzdump "snapshot" mode for LXC. for LXC, snapshot mode needs a snapshot capable storage, like the ones I gave in my previous post. non-thin LVM has a kind of snapshot which PVE does not support, so neither storage snapshots nor snapshot mode will work for LXC containers.
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Reactions: Andrii


Jul 6, 2016
Can I convert LVM to LVM-Thin without the data loss?
lvconvert --type thin-pool pve/data
Jun 21, 2011
Hi! I have Proxmox 4.3-3. lxcfs is version 2.0.4-pve1. I have a server with a single LXC container running as a Samba server on ZFS storage on localhost. It does not mount any external filesystem. It is set to backup to local folder storage. If I set the scheduled backup to use suspend mode, once in a while (like on 33% of backups), it hangs on "starting final sync", the backup never completes (I have waited for 4 days to make sure) and I have to run "pct unlock <VMID>" to be able to restart the cointainer (otherwise it reports "CT is locked (backup)"). Here you are the backup log:
INFO: starting new backup job: vzdump 100 --mailnotification always --mailto xxx@xxx.it --quiet 1 --storage local --compress lzo --mode suspend
INFO: Starting Backup of VM 100 (lxc)
INFO: status = running
INFO: backup mode: suspend
INFO: ionice priority: 7
INFO: CT Name: sambaserver
INFO: starting first sync /proc/2916/root// to /mnt/vztmp/vzdumptmp29573
INFO: Number of files: 126,697 (reg: 112,593, dir: 10,605, link: 3,464, dev: 2, special: 33)
INFO: Number of created files: 126,696 (reg: 112,593, dir: 10,604, link: 3,464, dev: 2, special: 33)
INFO: Number of deleted files: 0
INFO: Number of regular files transferred: 112,586
INFO: Total file size: 98,200,070,529 bytes
INFO: Total transferred file size: 98,199,810,113 bytes
INFO: Literal data: 98,199,810,113 bytes
INFO: Matched data: 0 bytes
INFO: File list size: 5,963,276
INFO: File list generation time: 0.020 seconds
INFO: File list transfer time: 0.000 seconds
INFO: Total bytes sent: 98,232,382,306
INFO: Total bytes received: 2,229,895
INFO: sent 98,232,382,306 bytes received 2,229,895 bytes 25,672,184.03 bytes/sec
INFO: total size is 98,200,070,529 speedup is 1.00
INFO: first sync finished (3826 seconds)
INFO: suspend vm
INFO: starting final sync /proc/2916/root// to /mnt/vztmp/vzdumptmp29573


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