[SAC] Options for controlling I/O Bandwidth of backups etc

[Alex Mandel]

I've been pondering how we could better manage backup processes,
mirroring of downloads etc without the potential to slow everything down
to a halt. Aside from my idea on the wiki page to stagger backup times
between 3 distinct time segments;
See very bottom of
http://wiki.osgeo.org/wiki/Infrastructure_Transition_Plan_2010#Questions_to_ask_OSL.2FOurselves

There seem to be some relatively easy to implement options.
A little research has revealed a few options
1. Limit the bandwidth on rsync processes
http://www.cyberciti.biz/faq/throttle-disk-io-rate-limit-disk-io/
2. Use some tools to control QoS such as ionice
http://www.cyberciti.biz/tips/linux-set-io-scheduling-class-priority.html

Any thoughts?

Alex