On Thu, 24 May 2012, Edgar Fu? wrote:
I then build a RAID 1 with SectorsPerSU=128 (e.g. a 64k stripe size) on two
of these discs, and, after the parity initialisation was complete, wrote
to [r]raid0b.
On the raw device, throghput ranged from 4MByte/s to 97MByte/s depending on bs.
On the block device, it was always 3MByte/s. Furthermore, dd's WCHAN was
"vnode" for the whole run. Why is that so and why is throughput so low?
What is the partition alignment on the raid?
There's a discussion of the alignment impact on my raidframe how-to on
the NetBSD WiKi.
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