flat storage migration?

[mo_]

Hi,

Im looking at Proxmox 3.0 cluster that is connected to 2 distinct Ceph clusters (dont ask). Now unfortunately somebody set up a KVM with a 4TB disk. the actual usage is like <100GB but I have noticed that storage migrations actually do reserve the space on the target storage, which is unfortunate. Is this something that got fixed already in 3.2 or is there another way to storage migrate such a VM short of taking a backup (takes like 20 hours) and restoring it on the other storage?

 

[wahmed]

This issue is not really on Proxmox side. When you first create a VM on Ceph RBD it does create a thin provisioned virtual disk, but when you migrate or restore it actually uses up the entire size of the virtual image. One way to shrink it back is to fill up with Zeros i believe.

[ 2 Distinct Ceph cluster? Totally understandable. ]

 

[mo_]

Well the backup sparses things up, I wouldve hoped itd be possible to only write non-null sectors to the RBD during storage migration.

But I suppose Id be better of duplicating the VM and rsyncing the contents then I suppose... thanks anyhow