> -----Original Message----- > From: xfs-bounces@xxxxxxxxxxx [mailto:xfs-bounces@xxxxxxxxxxx] On Behalf > Of Eric Sandeen > Sent: Thursday, April 07, 2016 4:22 PM > To: xfs@xxxxxxxxxxx > Subject: Re: Determining whether stripe unit and stripe size were > detected correctly > > > > On 4/7/16 3:16 PM, Simpson, John R wrote: > > Greetings, > > > > > > > > I'm in the process of tracking down lower than > expected performance and occasional blocked tasks on some internal file > servers with XFS datastores. Several sources have pointed out the > importance of using the correct stripe unit and stripe size when > formatting and mounting XFS filesystems, and that XFS can detect these > values for some, but not all, hardware RAID controllers. The servers in > question are PowerEdge R510b servers with PERC H700 controllers. > Datastores are RAID5 with a 128K stripe. > > Is there any way to determine if the stripe unit and > stripe size were detected correctly? These values were not specified > when the filesystems were formatted or mounted. If they were not > detected, is there any way to determine them programmatically? > > If this is not the correct forum for this question > please point me in the right direction. > > > > > > > > Best regards, > > > # xfs_info /DS01 > > > > meta-data=/dev/sdb1 isize=256 agcount=5, > agsize=268435455 blks > > = sectsz=512 attr=2, projid32bit=0 > > data = bsize=4096 blocks=1212415488, > imaxpct=5 > > = sunit=0 swidth=0 blks > > sunit == swidth == 0, so no geometry is present on this filesystem. > > > naming =version 2 bsize=4096 ascii-ci=0 > > log =internal bsize=4096 blocks=521728, version=2 > > = sectsz=512 sunit=0 blks, lazy- > count=1 > > realtime =none extsz=4096 blocks=0, rtextents=0 > > mkfs.xfs uses values exported by the block device, and can be seen by > using blockdev to query them, i.e. > > blockdev --getiomin --getioopt /dev/sdb1 > > If it returns 0, no geometry is exported by the device, and you'd need > to use your own knowledge of the device to set appropriate values (and > to properly partition on aligned boundaries as well) > > -Eric > Thank you, I was hoping sunit == swidth == 0 meant 'auto-detected' but suspected that wasn't the case. It looks like blockdev is reporting 0 for getioopt so we'll have to calculate and supply sunit and swidth. I believe the partition is properly aligned, I used the following. Any suggested improvements are appreciated. parted --align optimal --script $device mklabel gpt mkpart -- primary 1 -1 Blockdev reports: # blockdev --getiomin --getioopt /dev/sdb1 512 0 Is there a way, other than testing, to determine the potential performance improvement gained by providing the geometry? John > _______________________________________________ > xfs mailing list > xfs@xxxxxxxxxxx > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
