When choosing options for disk backup I am given the choice between
If I am wanting to do bare metal restores from a failed system I would think I would need all internal disks. Asking if this logic is correct? The computers have 4 partitions on the disk, I think I would need them all and the best choice would be “all internal disks” ?
This depends on what you have on those internal disks (or partitions), how important preventing its loss is to you, how much space this content consumes, and how much available space you have in your urbackup storage area to back it all up.
Maximum protection would be to back everything up. Does urbackup have the disk space available to do that? If the content of all your internal drives added together amounts to, say, 1Tb, then you probably want at a very minimum 2Tb of available urbackup storage available. That may not even do it, if you start doing both image backups and file backups. I would go for 4Tb myself. Disk space is cheap these days. Don’t skimp.
If you have some stuff on your internal drives that you are not sure if you want to backup or not, then look into urbackup’s “virtual clients”. then you can backup the questionable stuff using a virtual client and if you decide later that you really don’t need these questionable backups, you can simply delete the virtual client and recover the backup disk space.
If you use only one regular client to backup up everything, including the questionable stuff, it is more difficult to remove the questionable stuff from urbackups storage later, if you change your mind.
If in doubt - back it up. You will never regret that later. The cost to buy additional urbackup storage disks now is trivial compared to the regret you would have later if you find that you did not backup something that you wish you had. This includes trying to fine tune your backups. For example, you do not need to backup cache files. Those are temporary, intended to speed things up, but not a requirement for the system. However, the effort and/or experience to know how to exclude cache files without accidentally screwing something else up may not be worth it. Just backup the silly cache files along with everything else. All’s that does is waste a little bit of disk space. But in the grand scheme of things it’s not going to hurt anything, isn’t going to take up all that much space (usually), and may be worth it just for the simplicity and peace of mind it gives you regarding your backups. Remember, disk space is cheap, so often times simplicity will win out over configuration minutia.