Our migration from our old fileservers to our new fileservers has been a slow process that's hit some rough spots. Still, we've hit a distinct point that I want to mark: this past week we reached the point where we did 'zpool destroy' on one old fileserver's old pools and powered down its backend disks.

While we can migrate rapidly when we need to, our decommissionings usually go slowly. Unless we need the rack space or the hardware for something, we mostly leave old servers and so on running until they get annoying for some reason. This makes the whole thing a gradual process, instead of the big bang that I expect some people have. In our case we actually started losing bits of the old fileserver environment almost a year ago, when we started removing bits of our old test environment. More recently we used our hot spare fileserver as a hardware donor during a crisis; we're unlikely to replace it, although we theoretically could.

(In fact we decommissioned this particular fileserver mostly because it was getting annoying. One of the disks in one of its backends failed, causing us to get plaintive email about the situation, so we decided that we wanted to power off all of the remaining disks to preserve them as potential future spares. Destroying the pools instead of just exporting them insures that the disks won't be seen as still in use by a ZFS pool if we reuse them later.)

On the one hand, this is a trivial step and the fileserver had already had its last filesystems migrated a week or so before this (and we've destroyed some migrated filesystems for various reasons, which is far more irreversible than 'zpool destroy'). On the other hand, it simply feels significant. In a way, it makes the whole thing real; we've decisively torn down what used to be a production fileserver. I can now really believe in a relatively near future where we have no Solaris 10 machines any more.

(It won't be an immediate future; given recent issues all remaining filesystem migrations to the new fileservers are probably on hold until January. In general we try not to do too much in late November and early December due to the university's long holiday around Christmas and the end of the year.)