On Wed, Nov 13, 2013 at 08:10:29AM -0800, Christoph Hellwig wrote: > On Wed, Nov 13, 2013 at 05:40:59PM +1100, Dave Chinner wrote: > > From: Dave Chinner <dchinner@xxxxxxxxxx> > > > > Large filesystems or high AG count filesystems generally have more > > inherent parallelism in the backing storage. We shoul dmake use of > > this by default to speed up repair times. Make xfs_repair use an > > "auto-stride" configuration on filesystems with enough AGs to be > > considered "multidisk" configurations. > > > > This difference in elaspsed time to repair a 100TB filesystem with > > 50 million inodes in it with all metadata in flash is: > > > > Time IOPS BW CPU RAM > > vanilla: 2719s 2900 55MB/s 25% 0.95GB > > patched: 908s varied varied varied 2.33GB > > > > With the patched kernel, there were IO peaks of over 1.3GB/s during > > AG scanning. Some phases now run at noticably different speeds > > - phase 3 ran at ~180% CPU, 18,000 IOPS and 130MB/s, > > - phase 4 ran at ~280% CPU, 12,000 IOPS and 100MB/s > > - the other phases were similar to the vanilla repair. > > > > Memory usage is increased because of the increased buffer cache > > size as a result of concurrent AG scanning using it. > > Looks good as long as you stick your promise to clean up the magic > numbers later. Already got a prototype patch for it. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
