LXC backup INFO: mode failure - some volumes do not support snapshots

[brunoverdi]

Hi guys, what's up?

Is there any way I can backup a LXC container using snapshot mode without entering in 'suspend' mode instead?
Ps: Error / Warning: mode failure - some volumes do not support snapshots - What kind of volume would LXC snapshot backup be possible?

If possible, could anyone detail for me?

Thanks

 

[fabian]

your storage needs to support snapshots for all volumes - post the full log and your storage.cfg maybe?

 

[brunoverdi]

Yes... After I post it I found this: https://pve.proxmox.com/wiki/Storage and realize that only a few storages support snapshots...
ZFS and LVM-Thin for example...

We're gonna do a test here with ZFS.

Thanks for the reply

 

[zecat]

Hello, just to clarify, https://pve.proxmox.com/wiki/Storage indicates n/a for snaphot mode with proxmox backup server. Does this mean that snapshot is not compatible with proxmox backup server ? I tried with a btrfs andproxmox backup server as remote target, but get a "mode failure - some volumes do not support snapshots".

Thank you for your help on this subject.

 

[fabian]

for containers, the source storage (where the container mountpoint volumes are stored) need to support snapshots. the backup target storage type is irrelevant (although it's a bit confusing that each backup is also called a "snapshot" on the PBS side ). the table in the docs justs indicate you cannot snapshot things stored on a PBS storage (which is the case - it can only storage backup archives, which are immutable after being created anyway).

 

[zecat]

Thank you @fabian for your answer, it's clear now. However, I set up proxmox on btrfs and get a "mode failure - some volumes do not support snapshots" when running backup. Is it due to the fact that it is not stable (technology preview) at this time ? Or maybe I missed something?
Regards,
Thierry

 

[fabian]

please post the full container config..

 

[zecat]

Proxmox host FS is :
Filesystem Type Size Used Avail Use% Mounted on
/dev/md0 btrfs 477G 3.9G 473G 1% /

udev devtmpfs 32G 0 32G 0% /dev
tmpfs tmpfs 6.3G 848K 6.3G 1% /run
tmpfs tmpfs 32G 37M 32G 1% /dev/shm
tmpfs tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/fuse fuse 128M 16K 128M 1% /etc/pve
tmpfs tmpfs 6.3G 0 6.3G 0% /run/user/0

And the CT conf is :
arch: amd64
cores: 1
features: nesting=1
hostname: test
memory: 512
net0: name=eth0,bridge=vmbr1,firewall=1,hwaddr=88:83:FC:A6:21:2D,type=veth
ostype: debian
rootfs: local:100/vm-100-disk-0.raw,size=8G
swap: 512
unprivileged: 1

 

[fabian]

but "local" is likely just a directory storage, not a BTRFS one.. could you post /etc/pve/storage.cfg as well?

 

[zecat]

but "local" is likely just a directory storage, not a BTRFS one.. could you post /etc/pve/storage.cfg as well?

Ok, I thought that the "/" as a BTRFS was enough, and "local" as a subdir of "/" should work .
But following your question, I realized my misunderstand. So I created a new storage type "BTRFS Dir" in "/var/lib/vz_btrfs_test", and created a CT inside, and now backup of this CT as a snapshot works in snapshot mode !

So now 101.conf is :
rootfs: test_btrfs:101/vm-101-disk-0.raw,size=8G

and storage.cfg is :

btrfs: test_btrfs
path /var/lib/vz_btrfs_test
content iso,snippets,rootdir,images,backup,vztmpl
prune-backups keep-all=1


Thank you a lot to have pointed me in the right direction.

Does "technology preview alert" means that this is not advised to use in production as raw CT content ?

Regards,
Thierry

 

[fabian]

Does "technology preview alert" means that this is not advised to use in production as raw CT content ?

it means there might be some rough edges and bugs still lurking, and that it is not covered by enterprise support.