a disk image is not resource effective, and i would highly recommend against it. reasons:
- if you have a server with let's say 200 gb of disk space used, then you would have to copy that 200 gb (and by no means it will take 5 minutes) every day or with what frequency you wish to copy, that server will have to support a lot of cpu usage, and unnecessary disk i/o, slowing down services for your customers, and we don't want that.
- on the other hand, you could have a local drive added, and configure whm to take backups to that disk, and rsync the disk contents to our backup location - that is the preferred way to do it.
it should not be that hard to restore a server, provided that you backup core config files that would help you restore the server much faster than usual.
- by doing rsync backups, you would also save lots of bandwidth per day, and a lot of i/o that is generated doing the backup copy process.
i would understand if you do images backups for virtual machines, but for a dedicated server, it kinda doesn't make sense.