On Fri, Jul 10, 2015 at 03:59:48PM +0000, Hogan Whittall wrote: > Hi Dave, > > Thanks for the reply, we can certainly try with the smaller log, > but IIRC the performance hit wasn't because the disks were busy, > it was the controller itself trying to determine what changed and > then write that to disk. That makes no sense to me - the controller is almost never the IO limitation in a hardware RAID when random small IO is being issued by the host. > Smaller anything should help the > controller be able to cope better, but that's not really a > solution. > > Doing disk write performance tests on these systems produce very > different results, they are capable of much more I/O than what was > being triggered with this issue. > > Back to why I think this should be considered a bug, by 2.9.6 > setting 0 as the default for sunit/swidth and 3.1.1 having no way > to set 0 for sunit/swidth the newer versions behave differently False: # man mkfs.xfs .... noalign This option disables automatic geometry detection and creates the filesystem without stripe geometry alignment even if the underlying storage device provides this information. IOWs: # mkfs.xfs -d noalign .... Will do exactly what you want. Or alternatively: # mkfs.xfs -d sunit=0,swidth=0 .... Or perhaps just turning of log stripe unit alignment will be enough: # mkfs.xfs -l sunit=1 .... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
