Reiser and Run
While working through today's code and test to-do list, I ran out of space on a required SLES 10 file system. Fortunately, it was LVM-managed, and there was plenty of room in the volume group to stretch this thing. I vaguely recalled just enough LVM command names (lvdisplay, lvresize) to look up the process.
Extending the logical volume was super-fast, but resize2fs failed with "can't resize a mounted filesystem!" No way! This was a 2.6.16 kernel: not exactly hip, but current enough to allow online resizing.
I checked mount points and saw that this was a reiserfs file system. ReiserFS?! Sure, that was once the SLES way, but I thought it had been deprecated since the arrest, if not for murder-related reasons, then for security and/or functional ones. Fortunately, the LVM HOWTO rescued me: it told me to use resize_reiserfs instead, and that worked like a charm.
I'll try to remember this in case there's a next time. If not, this blog post will remind me. :-)