Hi Jamie,
I am running into this problem whenever I try to use the filesystem backup to backup to a remote server over SSH.
sh: 1: /usr/lib/tar/rmt: not found tar (child): user@123.123.123.123:/home/do/backups/midnight: Cannot open: Input/output error tar (child): Error is not recoverable: exiting now
I have added this under the backup options for Path to rmt on remote system /usr/sbin/remote
Searching online for this error I cam accross this old thread - http://t95660.web-webmin-general.webdiscuss.info/remote-backup-files-t95...
Where you have mentioned it. " I tried this out myself just now, as it seems that only Debian uses the wrong path. It really looks like a bug in the tar command (or at least Debian's package of it). I will add an option to Webmin in the next release for setting the --rmt-command flag though."
Is this still a bug on Ubuntu? I am using Ubuntu 12.04 LTS and 14.04 server.
Attempt test restore after backup to verify? If this option is set to No. The filesystem backup to remote server works.