On Sat, Jun 01, 2019 at 05:39:25AM +0000, Andy Smith wrote:
> On Fri, May 31, 2019 at 09:43:35AM +0800, Guoqing Jiang wrote:
> > There are some optimizations in raid1's read_balance for ssd, unfortunately,
> > raid10 didn't have similar code.
[…]
> Is it just that no one has tried to apply the same optimizations to
> RAID-10, or is it technically difficult/impossible to do this in
> RAID-10?
Guoqing sent me a patch off-list that implements these same device
selection optimizations to RAID-10, and it seems to work. RAID-10
random read performance in this setup is now the same as RAID-1
(both very near to fastest device) and sequential read is even
better than RAID-1.
http://strugglers.net/~andy/blog/2019/06/06/linux-raid-10-fixed-on-imbalanced-devices/
Cheers,
Andy
