I've recently lost my Proxmox server, one of the HDD died. I rebuilt the server and when I connected the iscsi NAS proxmox did not import any of the stored VMs. Is there a way to import all the VMs into the Proxmox library?
The VM configurations are stored on the root disk of the PVE system (/etc/pve/{qemu-server,lxc}). If you lost these, then you have two options:
Restore from a 'vzdump' backup (these include the configs too)
Create new VMs with the same VMIDs and attach the existing disks to them (e.g. attach a small disk to be removed later in the wizard, then run qm rescan, pct rescan after creating, then your old images should show up as 'unused disks' as long as the IDs match).