On Thu, Dec 10, 2015 at 8:50 PM, Mark Knecht <markknecht@xxxxxxxxx> wrote: > > > On Thu, Dec 10, 2015 at 5:19 PM, Dallas Clement <dallas.a.clement@xxxxxxxxx> > wrote: >> >> <SNIP> >> >> One thing I didn't see in this thread was a check to make sure your >> >> alignment is on the physical sector alignment if you're using 4K >> >> sectors >> >> which I assume drives this large are using. >> > >> > Yes, these drives surely use 4K sectors. But I haven't checked for >> > sector alignment issues. Any tips on how to do that? >> >> According to parted, my disk partition is aligned. >> >> (parted) align-check >> alignment type(min/opt) [optimal]/minimal? >> Partition number? 6 >> 6 aligned >> >> Partition Table: gpt >> >> Number Start End Size File system Name Flags >> 1 2048s 10002431s 10000384s primary >> 2 10002432s 42002431s 32000000s primary >> 3 42002432s 42004479s 2048s primary >> bios_grub >> 4 42004480s 42006527s 2048s primary >> 5 42006528s 50008063s 8001536s primary >> > 6 50008064s 7796883455s 7746875392s primary >> >> 50008064 / 4096 = 12209 > > I think you want to divide by 8 as 8*512 = 4096 but you're likely ok > on all of them. Partitioning tools are better about that these days. > > Looking back I didn't see what sort of controller/s you have all these > drives attached to. If you're spinning in IO loops then it could be a > driver issue. > > I would suggest googling for causes of iowait cycles and post > back additional questions. > > Good luck, > Mark Hi Mark. I have three different controllers on this motherboard. A Marvell 9485 controls 8 of the disks. And an Intel Cougar Point controls the 4 remaining disks. > If you're spinning in IO loops then it could be a driver issue. It sure is looking like that. I will try to profile the kernel threads today and maybe use blktrace as Phil recommended to see what is going on there. This is pretty sad that 12 single threaded fio jobs can bring this system to its knees. -- 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
