Excessively large diffs

[jskirke]

Hi ayufan,

first of all, thanks for your great contribution!
Currently, I am testing your patches for my home server / lab.

What makes me wonder is, that the diffs vary depending on the vm type depending their size.

E.g. an LXC container holding a db and some data results in megabytes up to some gigabytes while a Windows VM running as file server with ~200gb of data results in a diff of ~100gb size after a day without many changes. Qemu agent seems to run, as I can ping the VM without errors.
Is there another aspect I could have a closer look on to remedy this circumstance?

Thanks in advance!

PVE 5.2-2

[freefloris]

My method:

1. Clean Windows
2. Defragment the disk
3. Create a backup
4. Restore backup
5. Shrink VM : https://pve.proxmox.com/wiki/Shrink_Qcow2_Disk_Files

[ayufan]

Yes, you have to shrink qcow2, or trim lvmthin storage, or fill with zeros for efficiently storing data. Otherwise, diffs gonna be large, as it will persist bloat.