Amount of write to SSD/HDD when backup job is executed for VMs

[Analog Mind]

Hello,

Apologize if that topic was already posted/answered somewhere here, I haven't found any exact matching yet...

I'm planning to use Proxmox VE on my home server mainly for few VMs/containers which will run file server, Nextcloud, etc. What I'm interested in is how much data write will occur for each backup job run when there were no data changes on my virtual disks? I'm using SSDs, so wearing is smth which I consider when deciding to use 'in-built' PVE capabilities or try some rsync-like solutions on the VM side to eliminate rewrites of unchanged data. As far as I understand now, PVE do not care about virtual disks content and does just 'copy-paste' stuff for 'single big file' as host system see the virtual disks. Could you clarify more on this topic please?

Thanks!

 

[Kingneutron]

Setup proxmox backup server and do some tests. Dedup alone is worth it, but also has nice extra features like fine-grained restore.

I have 2 instances of pbs to complement each other, 1 is an ancient 4-core-i3 laptop with 8GB RAM and a 1TB SSD.
The other is a virtualbox VM on my 2013 Mac Pro with pretty much the same specs.

The core-i3 is so old, it doesn't support AES and won't do full 2.5Gbit speed with a usb3 adapter. IDK how much raw data (26 VMs and 7 LXC containers) on my pve host is being backed up, but the pbs destination is using something like under 150GB with the dedup and keeping the last 3 backup versions. My pve rig is using a mix of spinning disks and nvme ssd, full backup finishes in a little over 31 minutes in my case. YMMV

 

[Analog Mind]

Yeah, I tried to setup PBS on a separate physical node but that's overkill for my purposes. Also thought about PBS WOL right before the backup job start. But PVE is trying to ping suspended PBS all the time with no success thus overloads logs with tons of messages. What about PBS setting up on VM? Then it should be possible to keep datastores on separated virtual disks

 

[Kingneutron]

https://github.com/kneutron/ansites...proxmox-fix-pbs-storage-down-spamming-logs.sh

You /can/ setup pbs in a vm, but then you have a chicken/egg situation if something important dies and you need to restore your environment. This is why I keep VM backups separate from the server they're intended to restore to.

You could setup pbs on like a win10 desktop with virtualbox, but you'll be crippling your network backup speed even with virtio. The one I setup is totally secondary/tertiary backup

 

[Analog Mind]

Thank you for useful link! I will think about it.

There should be good enough tradeoff actually: say keep PBS on VM and it's datastores on other than data SSD. This should provide some protection from hw failure like disk failure and allow all the sw benefits of PBS. Hmm... However I have a tiny nettop box based on AMD AM1 Athlon 5350 with 16GB of DDR3 which looks a nice candidate for PBS