[SOLVED] Slow Parity Sync ~ 5 MB/sec. 1 drive slower than others

[dmc72]

Unraid 6b15 in an ESXI VM, 4Gb,1 CPU, 2 Supermicro controllers passed thru to Unraid, Norco 4224.

 

I've been getting beat up by some hardware troubles for the last few weeks. All started with a power failure while UPS was not tied in. Hard drives randomly showing as missing, flash drive not bootable, parity errors during rebuild from hard drive dropping out. 

 

Anyway, I seem to have the hardware troubles cleared, but still getting an odd behavior. I am rebuilding parity (after doing a 'New Config') onto a new 4tb drive(all data drives are 3tb). Speeds are running about 5 MB/s where i usually see about 100MB/s.  Disk 5 is a 7200rpm HGST NAS and is showing only about 5% of the reads as all the other drives, but is showing no errors on smart reports. The parity rebuild says it will take about 8 days, which is terrible.

 

If parity rebuilds successfully I plan on swapping the drive to another slot. If that doesn't fix it, I will try a new drive.

I am curious if anyone has seen this big difference in reads and what can cause it. If it is the drive, do I need to prove errors to RMA it. Is there anything I can do to get its speed back? Any suggestions on other stuff to check are welcome.

 

Thanks!

-Dave

syslog-5-20-15_slow_parity_sync_-5MB-sec.zip

disk_5_SMART.txt

[Bungy]

I was seeing similar issues with the AOC-SAS2LP-MV8 cards. After a certain amount of time, the drives on that controller would slow down. I can't provide you with a fix if that's your problem since I switched to a Dell card flashed to M1015.

[dmc72]

Thanks, I have been thinking of switching 1 of the cards to a M1015 to see if it fixes some random slowdowns that I have seen.

What i am seeing now is different. there is no change at all in the speed, it stays right at 5.3MB for 2 days now. Its so frustrating to watch!

 

I added an updated screenshot. It just shows how much of a difference there is between drives.

 

-Dave

[dmc72]

Just wanted to close this out now that my speeds are back to the 100MBs range.

 

I'm happy its working but don't understand what was causing the trouble. My disk #5 was only running at 5.3MB/s no matter if it was on the AOC-SASLP-MV8 or the AOC-SAS2LP-MV8. There was also no change if I swapped ports with another drive that was at full speed.

 

I ended up changing out both MV8 cards for a M1015 + RES2SV240 expander and is working great now. I wish I had done this from the start.

 

I have a Norco 4224 and want to give a reminder to anyone that gets a Norco case to double check all the backplane screws. While I had my case open, I was cleaning out the dust and cobwebs and found about half of the backplane screws were loose. I don't know if I missed tightening them when originally built or if they loosened over time. So if you open your case for anything, take a few seconds to check the screws.

 

-Dave

[Bungy]

Just wanted to close this out now that my speeds are back to the 100MBs range.

 

I'm happy its working but don't understand what was causing the trouble. My disk #5 was only running at 5.3MB/s no matter if it was on the AOC-SASLP-MV8 or the AOC-SAS2LP-MV8. There was also no change if I swapped ports with another drive that was at full speed.

 

I ended up changing out both MV8 cards for a M1015 + RES2SV240 expander and is working great now. I wish I had done this from the start.

 

I have a Norco 4224 and want to give a reminder to anyone that gets a Norco case to double check all the backplane screws. While I had my case open, I was cleaning out the dust and cobwebs and found about half of the backplane screws were loose. I don't know if I missed tightening them when originally built or if they loosened over time. So if you open your case for anything, take a few seconds to check the screws.

 

-Dave

I felt the same way when I "fixed" my problems by switching out the cards. It wasn't satisfying that I didn't fix the problem but at least I don't have to worry about it anymore. I'm glad you got things working again!