Snapshot deletion too slow

[PatoGB]

Hi,

I have Proxmox 9, two hosts configured with iSCSI (10Gbps) to an IBM Flash System 5200 Storage, the deployment and migration of VMs works very well, but when I delete snapshots it is too slow, does anyone know how to improve this part or is it a flaw in the virtualizer?

Thanks,

 

[fiona]

Hi,
what storage type are you using for the VM disks? If the VM disks are qcow2 files on a network storage, removing snapshots is recommended to be done while the VM is shut down.

There is a tech preview of the snapshot-as-volume-chain feature, which allows much faster snapshot operations: https://pve.proxmox.com/pve-docs/chapter-pvesm.html#storage_lvm It can be configured for LVM or directory-based storages.

 

[PatoGB]

Hi Fiona,

The snapshot-as-volume-chain feature value is 1, disk is qcow2, and LVM.


Show task viewer:erase disk after delete snapshot (this is the process that takes too long), and it doesn't allow me to migrate the VM.

 

[fiona]

Oh, I see. Yes, that is because you have the saferemove flag enabled on the storage: https://pve.proxmox.com/pve-docs/chapter-pvesm.html#pvesm_lvm_config The VM shuold already be functioning fine and not be blocked by that removal, just other VM operations.

If you need that flag, I suggest to keep it. There is an improvement being worked on currently, to make this much faster when the storage supports discard: https://lore.proxmox.com/pve-devel/mailman.116.1755518974.385.pve-devel@lists.proxmox.com/