Hi Stan On 01/13/2015 09:43 PM, Stan Hoeppner wrote: > With your file sizes that seems a recipe for hotspots. What do the > controller metrics tell you about IOs per drive, bytes per drive? Are > they balanced? > They looked ok from 10000ft, but unfortunately, the controller is not that talkative :( >> After the arrival of "advanced format" HDD and SSDs we usually try to >> align everything to full 1 MByte or larger, just to be sure any >> combination of 512b, 4kb, ... will eventually align :) > > It's not that simple with striping. Partitions need to start and end on > stripe boundaries, not simply multiples of 4KB or 1MB as with single > disks. If you use non power of 2 drive counts in a stripe, aligning at > multiples of 1MB will screw ya, e.g. 12 drives * 64KB is a 768KB stripe. At the moment there are 16 disks (or 8 "data" disks), so here, power of 2 still prevails. But still, very valid remark! Cheers Carsten _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
