[pve-devel] [PATCH v2 qemu-server 1/1] implement external snapshot

[Fabian Grünbichler]

> DERUMIER, Alexandre <alexandre.derumier at groupe-cyllene.com> hat am 23.10.2024 16:31 CEST geschrieben:
> 
>  
> >>if we want the current volume to keep its name, and the snapshot
> >>volume to actually contain *that* snapshot's data, we need some sort
> >>of rename dance here as well.. i.e., rename the current volume to
> >>have the snapshot volume name, then snapshot it back into the
> >>"current" name. not sure what the proper qmp runes would be to
> >>achieve that?
> 
> I really to check that, but I would like to keep it as most atomic than
> possible (avoid stream, double snapshot, and all fancy stuff just to
> take a snapshot. because shit happen  ^_^ , and generally it'll happen
> when you'll take a snapshot with multiple disk, you'll to manage
> recovery and current state of differents volumes)
> 
> Another stupid way is to use generic name for snapfile (maybe with
> ctime inside the name), and create symlinks when snapshot is taken.(
> qemu follow symlink and use realpaths for backing chain). 
> (and for lvm, it can be done with metadatas).
> 
> I'll really try to find a way with renaming volume, I'll keep you in
> touch.

yes, that might work as well. it's a bit less "clean", since looking at the storage itself then requires this extra knowledge to know what's what, but it shouldn't be too bad hopefully? curious to see what you come up with :)