Am 13.08.2012 19:14, schrieb Florian Philipp: > Am 13.08.2012 16:52, schrieb Michael Mol: >> On Mon, Aug 13, 2012 at 10:42 AM, Michael Hampicke >> <[email protected] <mailto:[email protected]>> wrote: >> >> Have you indexed your ext4 partition? >> >> # tune2fs -O dir_index /dev/your_partition >> # e2fsck -D /dev/your_partition >> >> Hi, the dir_index is active. I guess that's why delete operations >> take as long as they take (index has to be updated every time) >> >> >> 1) Scan for files to remove >> 2) disable index >> 3) Remove files >> 4) enable index >> >> ? >> >> -- >> :wq > > Other things to think about: > > 1. Play around with data=journal/writeback/ordered. IIRC, data=journal > actually used to improve performance depending on the workload as it > delays random IO in favor of sequential IO (when updating the journal). > > 2. Increase the journal size. > > 3. Take a look at `man 1 chattr`. Especially the 'T' attribute. Of > course this only helps after re-allocating everything. > > 4. Try parallelizing. Ext4 requires relatively few locks nowadays (since > 2.6.39 IIRC). For example: > find $TOP_DIR -mindepth 1 -maxdepth 1 -print0 | \ > xargs -0 -n 1 -r -P 4 -I '{}' find '{}' -type f > > 5. Use a separate device for the journal. > > 6. Temporarily deactivate the journal with tune2fs similar to MM's idea. > > Regards, > Florian Philipp >
Trying out different journals-/options was already on my list, but the manpage on chattr regarding the T attribute is an interesting read. Definitely worth trying. Parallelizing multiple finds was something I already did, but the only thing that increased was the IO wait :) But now having read all the suggestions in this thread, I might try it again. Separate device for the journal is a good idea, but not possible atm (machine is abroad in a data center)
