From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: New XFS benchmarks using David Chinner's recommendations for XFS-based optimizations. Date: Mon, 31 Dec 2007 10:22:53 -0500 Message-ID: <4779094D.8050002@tmr.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Justin Piszcz Cc: xfs@oss.sgi.com, linux-raid@vger.kernel.org, Alan Piszcz List-Id: linux-raid.ids Justin Piszcz wrote: > Dave's original e-mail: > >> # mkfs.xfs -f -l lazy-count=1,version=2,size=128m -i attr=2 -d >> agcount=4 >> # mount -o logbsize=256k > >> And if you don't care about filsystem corruption on power loss: > >> # mount -o logbsize=256k,nobarrier > >> Those mkfs values (except for log size) will be hte defaults in the next >> release of xfsprogs. > >> Cheers, > >> Dave. >> -- >> Dave Chinner >> Principal Engineer >> SGI Australian Software Group > > --------- > > I used his mkfs.xfs options verbatim but I use my own mount options: > noatime,nodiratime,logbufs=8,logbsize=26214 > > Here are the results, the results of 3 bonnie++ averaged together for > each test: > http://home.comcast.net/~jpiszcz/xfs1/result.html > > Thanks Dave, this looks nice--the more optimizations the better! > > ----------- > > I also find it rather pecuilar that in some of my (other) benchmarks > my RAID 5 is just as fast as RAID 0 for extracting large files > (uncompressed) files: > > RAID 5 (1024k CHUNK) > 26.95user 6.72system 0:37.89elapsed 88%CPU (0avgtext+0avgdata > 0maxresident)k0inputs+0outputs (6major+526minor)pagefaults 0swaps > > Compare with RAID 0 for the same operation: > > (as with RAID5, it appears 256k-1024k..2048k possibly) is the sweet spot. > > Why does mdadm still use 64k for the default chunk size? Write performance with small files, I would think. There is some information in old posts, but I don't seem to find them as quickly as I would like. > > And another quick question, would there be any benefit to use (if it > were possible) a block size of > 4096 bytes with XFS (I assume only > IA64/similar arch can support it), e.g. x86_64 cannot because the > page_size is 4096. > > [ 8265.407137] XFS: only pagesize (4096) or less will currently work. -- Bill Davidsen "Woe unto the statesman who makes war without a reason that will still be valid when the war is over..." Otto von Bismark