[PVE-User] VM storage and replication

[Alex K]

Hi all,

I have setup a dual server setup, with latest proxmox v7.x. Each host with
its own local storage. No shared storage (CEPH, GlusterFS).

I understand I can have VMs hosted on top LVM with qcow2 disk images or on
top thin LVM as raw thin LVM volumes. On both cases I still keep the option
to be able to perform VM backups. Which one is the preferred way according
to your experience? I will try to do some quick tests on the IO performance
between the two.

Also, I was thinking to replicate the VMs from one host to the other. I
understand that for the Proxmox integrated replication feature I need ZFS
backed storage. As I am not much into ZFS, although I really enjoy FreeNAS
and its great features and will definitely look into it later, I was
thinking to prepare a custom script that would snapshot the LVM volumes
where the VM images reside and sync the VM disks from one host to the
other, using rsync, just for a local copy of them. Of course I will take
care to have an external media also to periodically export the VMs for
backup purposes, though I would like to have a local copy of the VM disk
images at the other host, readily available in case I face issues with the
external media or one of the hosts. What do you think about this approach?
Am I missing some other feature or better approach?

Regrading the sync/replication of the VMs between the hosts (without ZFS),
I was thinking also to have a dedicated local LVM volume for these periodic
backup jobs configured within Proxmox and then the custom script to just
rsync these backup images between the two hosts. This seems a simple one
though it increases the storage requirements, while with the previous
approach with the custom script, the script would snapshot, sync to the
other side and remove the snapshot without keeping a redundant local copy
of the disk image in the same host.

Sorry for the long read.
Appreciate any feedback.

Alex