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>
>>> 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 =
>> 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  striping
the raid6's with md raid0.