On Tue, 2006-05-09 at 16:32, Wouter Van Hemel wrote:
In real life on general purpose servers, the gains have been quite marginal, though. Filesystem change isn't a miracle cure for performance problems, obviously; if that's the problem, more disks to spread the transactions over make a much bigger difference I/O wise.
If you put a huge number of files in the same directory, the filesystem type can make a big difference in access time. Remember that before you can create a new file you must scan the current list first to see if that name already exists and the whole operation has to happen atomically with the directory locked. Filesystems that index the directories can help compared to a linear scan although there are some tradeoffs. Also some never shrink a directory when files are removed so you continue to scan all the empty slots.
Long ago I used a benchmark program called 'postmark' to test the speed of file creation/deletion operations that are typical in maildir environments. I haven't been able to find it recently although the last time I mentioned it someone said it was in the debian repositories and available via apt-get.
-- Les Mikesell lesmikesell@gmail.com