I have finally discovered what's going on here--at least, somewhat. I discovered that, when I encounter this bug, the Adblock Plus Firefox extension is in some kind of loop constantly rewriting one of its filter ini files. If I constantly $(ls -l) in the directory, I can see the same file constantly being rewritten, with its size going to zero, then up to the proper size, and back down to zero, then back up... It's the same filename being rewritten over and over again, and the file is about 1.5 MB, so that explains the slow but steady apparent loss of gigs of space. Since the space is recovered on reboot (or perhaps on logout when the eCryptfs volume is closed), I'm guessing it's some kind of bug related to truncating files and it not releasing the space when the file is truncated, so the rewriting eventually uses all available space. I can imagine a similar situation happening with BitTorrent disk I/O patterns. I haven't tried to reproduce the bug manually, outside of Firefox, but perhaps this info will help point you in the right direction. I'm not completely sure if the ABP extension is still exhibiting this behavior--perhaps an update to it has fixed its looping bug. Incidentally, in the few instances of my using torrents in eCryptfs, I haven't had any problems. Thanks for your work on this bug, Tyler. On Thu, Sep 13, 2012 at 6:26 PM, Tyler Hicks