Woah is a script that you can wrap commands with, and it will wait until the load average is reasonable before running them.
Similar to nice, you just start your command with woah and everything after
that will be run unchanged.
Say, if you have a lot of other things going on, and want your backup to wait for things to settle down...
woah tar -xvzf /tmp/foo.tar users/tim
Or you're running multiple things with xargs, but some are more expensive than others and you want to keep your machine somewhat responsive...
(cd /users; ls -d *) | xargs -P32 -n1 --no-run-if-empty woah tar /tmp/{} /users/{}
https://github.com/thatch/woah
Apache 2.0