Feb 24, 2019
I Notice that either proxmox backup and pve-zsync take more time to backupor zfs sync a VM if it s a Windows NTFS one.

I got a on same node Proxmox connected to same Freenas for backup
- several Linux Debian VM
- several Windows server VM

The linux VM backup or sync at maximxum speed of gigabit network between Proxmox and FREENAS
The Windows VM backup or sync are very slow (around 15 - 20 MB instead of 120 Mb )

Proxmox got zfs pool of 8 6TB WD RED and FREENAS zfs pool of 8 8 TB WED RED

I try to understand why i got difference of behaviour ...

Does file system inside VM impact ?


I guess only - many of the linux files are text so are highly compressible. This is not true for windows.

So in case of linux you see a much more speed because zfs will spent less time to read/search data on disk and this result in a good network speed(can fill very fast the network buffers). Not the case for windows!

In any case pve-zsync do not care what FS is in a VM. He cares about only disk blocks. You can verify the zfs compressratio for this vm.

Good luck / bafta
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