Mikael Abrahamsson <swmike <at> swm.pp.se> writes: > > On Thu, 25 Jul 2013, Wes wrote: > > > Why raid10 driver from Centos 6 has a 300% slower random write performance > > (random read stays the same) than Centos 5? > > > > Please share your ideas. > > ... > Does seekmark use barriers to assure that data has actually been written? > In that case it could be that 2.6.18 has different behaviour from 2.6.32 > when it comes to barriers and that explains the speed difference. > Yes, the kernels are as you stated. I used seekmark from http://learnitwithme.com/?page_id=267 and I am not so savvy to say if it uses barriers or not. Linear write speed (dd) is the same on centos5 and centos6. Just the random write (seekmark) got horrible. I found a way to disable barriers but for filesystems only. As I am testing block device not sure if barriers have something to it. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
