By default TKLBAM is designed to work with S3 automatically, and this is the easiest and safest option. In manual mode, TKLBAM can also work with non-S3 storage addresses, but this complicates usage and carries additional risks which you should make sure you understand first to avoid data loss.
Of all non-S3 manual storage targets, the local filesystem is the simplest options because you don't need to mess around with authentication credentials.
So assuming you want to store your backup at /mnt/otherdisk:
tklbam-backup --address file:///mnt/otherdisk/tklbam/backup tklbam-escrow /mnt/otherdisk/tklbam/key
And restore like this:
tklbam-restore --address file:///mnt/otherdisk/tklbam/backup --keyfile=/mnt/otherdisk/tklbam/key
Not as easy as the Hub-enabled "automatic" mode, but still easier than a conventional backup process. Linux supports mounting most types of storage devices (e.g., external harddrive, local network file share) to the filesystem though this can require extra configuration at the operating system level.
One of the main disadvantage of using a local storage target, besides the more complicated setup and maintenance process is that you won't be able to restore/test your backup in the cloud, or from a VM running in another office branch (for example).
Also keep in mind that a physical hard disk, even a RAID array, provides much lower data reliability than the 11 nines (99.999999999%) of Amazon S3
For this reason we recommend users use local backups to supplement cloud backups (e.g., providing fast local access).