Restore Failed because the Open-iSCSI Package is not Installed on the Proxmox Host (code 1982)

Situation

An instant restore plan finishes with the following error: Restore failed because the open-iscsi package is not installed on the Proxmox host (Code: 1982). Restoring to a Proxmox host requires the open-iscsi package, but it is not installed on the host...

Cause

The open-iscsi package is required during an instant restore to Proxmox because the system needs to discover, log into, and map the remote block storage target where the virtual disk is being restored. Without this package, Proxmox VE cannot communicate with iSCSI-based storage backends at the OS level to write the restored backup data, therefore restore to the Proxmox host will fail.

Solution

Install the Open-iSCSI package on the Proxmox host, then run the restore again. Refer to the Storage: iSCSI article for instructions on how to install it.