[pve-devel] [RFC qemu-server 9/9] restore_vm: improve checks if storage supports vm images

[Fiona Ebner]

Am 16.09.24 um 18:38 schrieb Daniel Kral:
> Improves checks if the underlying storage, where VMs are restored to,
> support the content type 'images'. This has been already the case for
> backup restores, but is refactored to use `check_storage_alloc` and
> `check_volume_alloc`.
> 
> Adds a check right before allocating a snapshot statefile and a
> fleecing VM disk image for backups for consistency with the storage
> content type system.
> 
> Signed-off-by: Daniel Kral <d.kral at proxmox.com>
> ---
> I am not sure about the changes to the statefile and fleecing images
> allocation as I've done them for consistency as well, but could cause
> sudden failures, especially if the logic in
> `PVE::QemuServer::find_vmstate_storage` could default to the hardcoded
> `local` storage, which fails on system where said storage does not
> support vm images (which is the default when installing PVE). Also the
> fleecing disk image storage is specified when starting the backup job
> with the `storeid` parameter in the PVE::VZDump::Plugin, where I'm not
> totally sure yet how it is used across the repositories.
> 

The part about the vmstate images should be part of the commit message,
but is also the reason we can't go for it right now. I do think the
fallback to 'local' can trigger for a VM without disks. We can add a
comment there to fix it up for Proxmox VE 9.0 (i.e. don't default to
local storage anymore, but require an explicit vmstate storage for such
VMs) where we can do such breaking changes.