On Thursday 2013-09-05 05:45, Linda Walsh wrote:
On POSIX (and linux), that blksize is the **preferred I/O size**. Which means it gets set based on the block-device and probably the filesystem.
A RAID uses stripe-size x width (#data stripes) as the "blksize" in the stat call.
So a RAID with 64k stripes & 12 data disks would have a stripe size of 768k. That stripsize is the optimal I/O size (and it isn't divisible by 2).
I cannot reproduce this with at least MD RAIDs in modes 0 5 and 6 using 64k×12 devices. The filesystem created on it reports 4096 for st_blksize, as does fstat on a block device fd when directly opened. So if you can describe your RAID more thoroughly.. -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org