I'm going to blame softdep: A long time ago when modifying large numbers of files on a machine with limited memory suddenly: the system became completely unresponsive, the disk light was on solid the poor little disk was rattling continuously. That went on for minutes.
The same job on the same machine without softdep ran slowly and with lots of moderate disk rattle but it completed normally. My guess is that softdep ran out of buffers and purged every one of them. All at once. Never enabled softdep after that. Geoff Steckel
