On Wed, 31 May 2017 19:20:10 +0700 CoolCold <coolthecold@xxxxxxxxx> wrote: > Creation (disable write intent bitmap, with bitmap all is much worse): > mdadm --create -c 64 -b none -n 20 -l 10 /dev/md1 /dev/sde /dev/sdf > /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk /dev/sdl /dev/sdm > /dev/sdn /dev/sdo /dev/sdp /dev/sdq /dev/sdr /dev/sds /dev/sdt > /dev/sdu /dev/sdv /dev/sdw /dev/sdx > > kernel: > [root@spare-a17484327407661 rovchinnikov]# cat /proc/version > Linux version 3.10.0-327.el7.x86_64 (builder@xxxxxxxxxxxxxxxxxxxxxxx) > (gcc version 4.8.3 20140911 (Red Hat 4.8.3-9) (GCC) ) #1 SMP Thu Nov > 19 22:10:57 UTC 2015 > > So, the question is - why cpu usage is so high and I suppose is a limit here? Definitely try a newer kernel, 4.4 at the very least; if no changes then 4.11. Also I would suggest to try out larger chunk sizes, such as 512 and 1024 KB. If you plan to use this long-term in production, also read up on the various RAID10 data layouts and their benefits and downsides (man md, search for "layout"; and search the Internet for benchmarks of all three). -- With respect, Roman -- 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
