Filesystem Backup Priority

I tried to find a way to reprioritize the tar process, which is initiated by filesystem backups. On the command line I would enter something like "nice -n 19 tar -czf archive.tar.gz /path/to/archive". In case such a nice / renice option should not exist, it should be implemented; in case that I have somehow overseen the option, I would highly appreciate a hint. ;)



Howdy -- you can set the priorities for scheduled jobs like that by going into Webmin -> Webmin -> Webmin Configuration -> Advanced, and there, take a look at the "CPU priority for scheduled jobs", "IO class for scheduled jobs", and "IO priority for scheduled jobs" options.

Sounds interesting ... what is the default for the three options and what would you recommend in order to prioritize the filesystem backup "a little bit"? And as these options affect all scheduled tasks: Is there a way to "nice" the tar processes individually? I am a little bit afraid of getting side effects by setting these global options.

It only affects jobs run by Webmin, it should be safe to experiment with some values there. Sorry there isn't a way to select that per-job though.

The "CPU priority for scheduled jobs" option refers to using "nice". If a nice value isn't specified, Linux uses "0" by default.

That might be the best place to start, to try some different nice levels (above 0).

The other options refer to using "ionice", which is a bit more complicated. There is documentation on that here: