We managed to waste a nice chunk of time today with a really simple mistake.

Our plan was to one of the two mirrored system drives in our Amanda backup server for a larger one, as part of the process of upgrading its operating system. What we accidentally did instead was to swap one of the extra spool space drives out. This did not work so well. (For a start, the system was a bit upset about not being able to mount the spool partition.)

You may remember that last week I said to always label (dying) hard drives you pull out of servers. Well, today I have a new lesson: always label hard drives, at least if a system has more than one. Having labels saying 'first system disk', 'sdc spool disk', and the like would have saved us some time and aggravation.

Unfortunately I don't know what the best way to do this is. Postit notes (what we used on the hard drive we pulled last week) seem a bit fragile. Clear scotch tape holding down very small pieces of paper?

(From this the clever reader will conclude that we didn't pause to label all of the hard drives in the server after we got the disks right. We were in a hurry to get it put back together and running. (This may turn out to be a serious mistake.))