All, When picking blockSize and segmentSize on RAID6 8+2 LUNs, I have see 2 optimal theories.
1) Make blockSize = # Data Disks * segmentSize e.g. in the RAID6 8+2 case, 8 MB blockSize = 8 * 1 MB segmentSize This makes sense to me as every GPFS block write is a full stripe write 2) Make blockSize = 32 (number sub blocks) * segmentSize; also make sure the blockSize is a multiple of #data disks * segmentSize I don't know enough about GPFS to know how subblocks interact and what tradeoffs this makes. Can someone explain (or point to a doc) about sub block mechanics and when to optimize for that? Thank you, Brian Marshall
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