Snapshots questions


New Member
Sep 11, 2023

I have two questions regarding snapshots.

  1. Why do VMs freeze when deleting a snapshot?
  2. How long can a snapshot be kept and not affect the VM if it is deleted? In this case, I'm also referring to question 1, as maybe an old snapshot will take longer to get deleted.
VM storage are in NFS for a group and other are stored locally in local-lvm. I've noticed this behavior in VMs stored in LVM: Those VM are Linux servers with a heavy load and drives with +300GB in size.

Depending on the storage technology, the snapshots are deleted synchronously or asynchronously. The latter is most of the time not a problem for the VM, because the deletion is spread over a longer timespan, whereare the first one is direct and therefore has the biggest impact on the performance of everything else on the storage if (and this is the second question) the snapshot references a lot of data that is to be deleted. It is very hard to predict how much load there will be on the system. Even just saying how big the snapshot is or how much space would be reclaimed can only be done by reading the data and the snapshot and compute the information then. Therefore you will not find this information anywhere directly.


The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!