On Wed, Sep 19, 2012 at 2:28 PM, Casper Bang <casper.bang@xxxxxxxxx> wrote: >> Anand Jain <Anand.Jain <at> oracle.com> writes: >> archive-log-apply script - if you could, can you share the >> script itself ? or provide more details about the script. >> (It will help to understand the work-load in question). > > Our setup entails a whole bunch of scripts, but the apply script looks like this > (orion is the production environment, pandium is the shadow): > http://pastebin.com/k4T7deap > > The script invokes rman passing rman_recover_database.rcs: IIRC there were some patches post-3.0 which relates to sync. If oracle db uses sync writes (or call sync somewhere, which it should), it might help to re-run the test with more recent kernel. kernel-ml repository might help. > Ext4 starts out with a realtime to SCN ratio of about 3.4 and ends down around a > factor 2.2. > > ZFS starts out with a realtime to SCN ratio of about 7.5 and ends down around a > factor 4.4. So zfsonlinux is actually faster than ext4 for that purpuse? coool ! > > Btrfs starts out with a realtime to SCN ratio of about 2.2 and ends down around > a factor 0.8. This of course means we will never be able to catch up with > production, as btrfs can't apply these as fast as they're created. > > It was even worse with btrfs on our 10xSSD server, where 20 min. of realtime > work would end up taking some 5h to get applied (factor 0.06), obviously useless > to us. Just wondering, did you use "discard" option by any chance? In my experience it makes btrfs MUCH slower. -- Fajar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
