April 17, 201511 yr Hi there, I am wondering if anyone can shed any light on my experience with slow parity checks. With a 6 TB parity disk, I am experiencing parity checks of ~25-35 MB/Sec. I let the parity check run for 6 hours and it only completed 10% Setup: Motherboard -ASRock Fatal1ty X99M Killer RAM - 2x8GB Crucial DDR4 (ECC) - CT8G4RFS4213 SATA card - Supermicro AOC-SAS2LP-MV8 CPU - Xeon E5-1650 v3 PSU - Seasonic Platinum Series X-860 Drives Currently, there are 5 data+parity drives in the server all connected in the same 5 bay enclosure. The parity drive and 3 data drives are 6 TB WD Red Drives. The last data drive is a 3 TB WD Red Drive. All of the drives are formatted as XFS. The data allocation on the drives is between ~ 20 GB on the 3 TB to ~ 5.1 TB on the most full 6 TB. The parity drive is connected directly to a SATA Port on the motherboard, while the data drives are each connected to a single port on the AOC-SAS2LP-MV8 card. I have 2x 512 GB SSDs that are used in a cache pool, connected to SATA ports directly on the motherboard. Troubleshooting I mounted each data disk as a disk share, and copied the same 8 GB file directly to the share. The write speeds that I saw were between 50-100 MB/sec. I then copied that 8 GB file from each data disk and saw sustained read speeds between 100-135 MB/sec. I disabled all dockers and ensured that there are no open streams but still achieve the same parity check speeds. I manually forced the mover and verified that there was no data that needed to me relocated from my cache drives. I've attached a syslog, can anyone provide any guidance or further troubleshooting steps? Could the server be having issues fully spinning all 5 disks up at the same time? If the drives aren't getting sufficient power could this cause them to work but at slower speeds? Thank you, Greg syslog.zip
May 1, 201511 yr Author D'oh! Time for me to hang my head in shame. It looks like my issue was caused by the PCI slot I was using for my SATA card. I never noticed, but now realize that in my previous configuration the card was being used at 4x. During my troubleshooting with my PCI passthrough for my VM, I switched my PCI slots and the card is being utilized at 8x. My parity check is currently running at ~140-150 MB/s. Good luck with your issue pkn, I hope you find a resolution!
Archived
This topic is now archived and is closed to further replies.