On 6/26/2011 4:26 PM, Stan Hoeppner wrote: > On 6/26/2011 12:53 AM, Marcus Pereira wrote: >> I got this idea at this post and was giving it a try: >> http://www.techforce.com.br/news/linux_blog/lvm_raid_xfs_ext3_tuning_for_small_files_parallel_i_o_on_debian > > Did you happen to notice that configuration has an IBM DS8300 SAN head > with tons of BBWC and *512* fiber channel disks? You have 8 disks. The DS8300 has up to 256GB of read/write cache: http://publib.boulder.ibm.com/infocenter/dsichelp/ds8000ic/index.jsp?topic=%2Fcom.ibm.storage.ssic.help.doc%2Ff2c_ds8300models922and9a2_1w2zq9.html It's difficult to convey how critical the DS8300, its 8 processor cores, and its gargantuan cache are in allowing the author to get away with using so many small XFS allocation groups. If his storage back end had consisted of plain HBAs or relatively small cache RAID cards connected to JBODs w/expanders, using that many small AGs would likely have caused serious performance degradation instead of a performance increase. Performance tuning is system specific. You read a Ferrari tuning manual and are attempting to apply that to tuning your Volkswagon. That's never going to work. -- Stan _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
