On 26/11/13 21:58, Pedro Teixeira wrote: > I created a Raid10 array with 16 sata 1TB disks and the array > performance > seems to be limited by the md0_raid10 taking 99% of one core and not > scalling to other cores. I tried overclocing the cpu cores and this > lead to > a small increase in performance ( but md0_raid10 keeps eating 99% of one > core ). > > I'm using: > - a phenom X6 at 3600mhz > - 16 seagate SSHDs ( sata3 7200RPM with 8GB ssd cache ) > - 4x marvell 9230 sata3 controllers ( 4 ports each ) pcie 2.0 2x > lanes. > - 8GB ram > - custom 3.12 kernel and mdadm compiled from latest source > > what I did to test performance was to force a check on the array, and > this > leads to mdadm reporting a speed of about 990000K/sec. The hard disks > report a 54% utilization. ( Overclocking the cpu by 200mhz increases the > resync speed a bit and the hdd's utilizartion to about 58% ) > > If I do the same with a raid5 array instead of raid10, them resync > speed > will be almost double of raid10, the harddisk utilization reported > will be > 98-100% and I can see at least two cores being used. AFAIK, the only way to make RAID10 use multiple cores is to actually create 8 RAID1 arrays, and then combine those into a RAID0 linear or RAID0 striped array. Each array will then create a new thread (total of 9 threads) which will then spread across all available cores. There is ongoing work happening to improve this, but I don't think it is available in any released kernel yet. Regards, Adam -- Adam Goryachev Website Managers www.websitemanagers.com.au -- 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
