I want to migrate VM made on 6.3 Proxmox (upgraded later to 7.4) to another server that's on 6.3. VM was originally created on local-lvm storage. Destination server is on Ceph storage pool. Can I safely restore said VM on Ceph?
I dont see why not. The backend storage is transparent to VM OS, as long as your backup/restore procedure is Proxmox storage aware (vzdump/pbs) - you should be fine.