On Sep 27, 2010, at 1:24 PM, Les Mikesell <lesmikesell at gmail.com> wrote: > On 9/27/2010 12:19 PM, Benjamin Franz wrote: >> On 09/27/2010 08:15 AM, Tom Bishop wrote: >>> So I'm in the process of building and testing a raid setup and it >>> appeared to take along time to build I came across some settings for >>> setting the min amount of time and that helped but it appears that one >>> of the disks is struggling (100 utilization) vs the other one...I was >>> wondering if anyone else has seen this and if so, is their a solution >>> for it...my 2 disks are 1 Samsung F3 1tb /dev/sdb and 1 Seagate >>> 7200.12 1Tb /dev/sdc...smartctl looks good on both.... >>> >>> >> >> [...] >> >> What is the output from 'cat /proc/mdstat'? > > Also, head position/motion is the usual limiting factor with disk > performance. Do you have other disk activity that will keep yanking the > head on the active drive away from the track currently needed for the > rebuild? Also, also, if any of the drives are operating in PIO mode (Legacy Mode) then rebuild times will be horrific, as well as performance afterward. Make sure all drives are in SATA/AHCI mode. -Ross PS look at svc_tm in iostat and make sure all drives are performing correctly. Maybe a bad cable or flakey port expander...