Using hdparm on a linode
If so, what would I need to watch out for so I don't screw up anything?
If not, would I be safe in removing it from my system (I'm running Gentoo, but I don't think the distro matters).
Not much of a point to running hdparm because Linode is (currently) a UML environment -- which makes device access virtual.
The "disk device" is, in reality, just a file on the host system, rather than an actual physical device with knobs you can tweak (DMA and stuff).
So… no, no benefit to hdparm on a Linode. I also run Gentoo, and it's not a problem to remove it, even if it screams bloody murder about it.
It's there because the systemwide profile mandates its presence. (Gentoo normally runs on non-UML hosts, so this is a reasonable choice. Just doesn't make sense with Linodes.)
Hmmm … that might be a good idea; create a Linode specific profile.
It let me do that. Haven't seen problems since then.