backup image mapping is read-only / vgimportclone not possible

[antubis]

hello,

i just tested your new proxmox-backup-server. dispite of the imho quite uncommon concept of decentralized backup management I need to be able to recover single files from a PVE vm backup image.
i tried mapping the image with proxmox-backup-client which works in general. however, if I map the disk into the source vm and a lvm is configured I have to resolv the double lvm names and ids with vgimportclone - which apparently needs write access.

can you either make the image writable (maybe a not good idea for backups) or do some kind of overlayfs to grant temp write access (without actual writing) to the images?

thanks a lot so far for your great products
antubis

 

[fabian]

you can actually already do that, just add 'snapshot=1' to the disk line in the VM config, and Qemu will buffer all writes in memory (and throw them away once the VM is shutdown). just make sure to not write more than your system can handle

 

[antubis]

good to know, didn't try that as i didn't map the disk through pve.
i just mapped it directly into the vm with an installed proxmox-backup-client. some (fake) write capability would be nice here, too.

 

[fabian]

in that case something like dm-clone external LVM thin snapshots should work (haven't tried it yet though).

edit: replaced dm-clone (which would a ctually transfer the full archive over time) with external LVM thin snapshots, which provide the semantic you want.

 

[fpausp]

hello,

i just tested your new proxmox-backup-server. dispite of the imho quite uncommon concept of decentralized backup management I need to be able to recover single files from a PVE vm backup image.
i tried mapping the image with proxmox-backup-client which works in general. however, if I map the disk into the source vm and a lvm is configured I have to resolv the double lvm names and ids with vgimportclone - which apparently needs write access.

can you either make the image writable (maybe a not good idea for backups) or do some kind of overlayfs to grant temp write access (without actual writing) to the images?

thanks a lot so far for your great products
antubis

Could you please try this and give us a feedback: HowTo restore a single file from Proxmox Backup Server (PBS)?