It seems like disk speed or CPU usage is limited for the restore function in WHM
Here is a screenshot of the /bin/cp process responsible for coyping the backup archive:

The archive is 9 GB and the process has been running for 1.5 hours, doesn't seem to go much above 2% CPU usage or 500K/s write
pidstat:

Here is a screenshot of the /bin/cp process responsible for coyping the backup archive:

The archive is 9 GB and the process has been running for 1.5 hours, doesn't seem to go much above 2% CPU usage or 500K/s write
pidstat:
