Data storage
is quite interesting, though should really just be a part of a role. Blimey are there some poor souls out there that just install drives, and use a selection of cp, dd, and rsync commands day in day out, perhaps with highlights of tar, gzip and bzip, and on a really fun day a smidgeon of bash compression.
Most of this can be automated in scripts, and monitored using scripts so it is a daft organisation that makes a role out of it, not that they don't exist I suppose. Managing file systems, recovering data, tweaking parameters projects sure it is a system admin role, but hey let them install and configure a server application every now and again, break up the monotony.