My no 1 issue with interworx right now, is the fact that backups and other intence operations tend to crank up the server load to unhealthy levels, and in some cases slow down the server or even (!) make it unresponsive.
I would really like to see a way to limit the ammount of resources a process or user can occupy.
What’s actually causing the load hit? “Backups” suggests i/o - if that’s the case, ionice works pretty well for that sort of thing, assuming it’s a cron job or similar causing the load. Ulimit is typically how users are limited. Obviously I don’t work for iworx, but these are the two things I’d suggest looking at first.
The main problem with limits is that they tend to be used as a band-aid in scenarios where demand for resources has outgrown available resources. Limits are most effective in scenarios like:
preventing a single user from forkbombing your sever with a stupid script
preventing backup script that needs to read 500k maildirs messages from disk during production hours from eating all available disk io
preventing a single user from eating your entire raid set with a misfiring backup script
they do not work well in scenarios where the same server is fighting with itself for resources.