Quotas

So: the quota file on an ext3 filesystem contains usage information ("How much disk space is this user using?"). It's updated when quotacheck is run, typically at boot time. After that the kernel has up-to-date info on quotas but doesn't write it to disk for performance reasons. So the kernel will deny/allow writes as necessary.

But the userland tools used -- particularly by users -- to monitor or report on quota state ("How much space am I allowed to use?") only uses those files. And those aren't updated unless quotacheck is run...which is either at boot time, or when called from cron. And to run it on a live system, you've got to turn off quotas to prevent corruption.

Bleah.

UPDATE: Near as I can tell, I was checking quotas while not realizing that quotas had been turned off for the filesystem I was checking, and thus quota reported bogus data.

CONCLUSION: I am on crack. BIG CRACK. Ignore me.