On Feb 1, 2014, at 11:47 AM, Stan Hoeppner <stan@xxxxxxxxxxxxxxxxx> wrote: > On 1/31/2014 12:35 AM, Chris Murphy wrote: >> Hopefully this is an acceptable way to avoid thread jacking, by >> renaming the subject… >> >> On Jan 30, 2014, at 10:58 PM, Stan Hoeppner <stan@xxxxxxxxxxxxxxxxx> >> wrote: >>> >>> RAID60 is a nested RAID level just like RAID10 and RAID50. It is >>> a stripe, or RAID0, across multiple primary array types, RAID6 in >>> this case. The stripe width of each 'inner' RAID6 becomes the >>> stripe unit of the 'outer' RAID0 array: >>> >>> RAID6 geometry 128KB * 12 = 1536KB RAID0 geometry 1536KB * 3 = >>> 4608KB >> >> My question is on this particular point. If this were hardware raid6, >> but I wanted to then stripe using md raid0, using the numbers above >> would I choose a raid0 chunk size of 1536KB? How critical is this >> value for, e.g. only large streaming read/write workloads? If it were >> smaller, say 256KB or even 32KB, would there be a significant >> performance consequence? > > You say 'if it were smaller...256/32KB'. What is "it" referencing? it = chunk size for md raid0. So chunk size 128KB * 12 disks, hardware raid6. Chunk size 32KB [1] striping the raid6's with md raid0. Chris Murphy _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
