A specific drive acts weird when I have power issues.

[snolly]

Hello all,

 

I am relatively new on Unraid, still going through the trial period, but I have a system set up, fully operational and loving it.

 

I used to have a Synology DS411j (I know it's old) with 4 x 3TB WD Red drives in it. It was working fine for most of the time (slow but fine).

 

When I had power failures, the Synology array would go into degraded mode indicating that drive in slot 1 had issues. If I removed the drive and reinserting it in the same slot the array would be rebuilt and I continued to use it. That happened twice over the course of 4-5 years. Only after a power failure.

 

Now that I built the Unraid system, I used the 4 synology drives along with some other spare drives that I had lying around. I have also connected Unraid server to an APC UPS and plugged the USB cable to it so it can know when to shut itself down in case of power failure.

 

Last night, my wife plugged a heating device and switched it on and power went off in the house for 20-30 seconds till I turned the power back on. Unraid server did not shut down, it run on UPS power (and sent me warning emails about this) for 20-30 seconds and then back to mains power.

 

When this occurred I also got an error e-mail that disk 5 (I presume the one that was in Synology slot 1) has errors and got disabled (red X mark next to it).

 

I google what to do, I downloaded diagnostics (which I cannot understand), and decided to re-enable the drive by unassigning it and reassigning it to the array (as I did with the Synology). It is currently being rebuilt.

 

I know this is risky stuff and the drive might completely fail but I am not willing to just throw it away as long as it is fine and it gets some kind of hiccups when power issues occur.

 

I am attaching the diagnostics as per Unraid wiki suggestion in case some of you guys might have some insight on what is going on. If the drive is indeed bad I will let the rebuild finish and I will replace it with the new one.

 

Thanks for your time and best regards,

George

 

PS : the drive in question is : WDC_WD30EFRX-68AX9N0_WD-WMC1T1075738-20190115-1102 disk5 (sdf) - DISK_DSBL

 

 

EDIT: Rebuilding is insanely slow. From a few KB/sec to top 2-3 MB/sec. All dockers are shut down, no other activity on the server apart from the disk rebuild. Is there anyway to check what causes the bottleneck? 8 of the drives are on an IT flashed LSI card that has no fan (only heatsink) on it. I read somewhere that this might get hot. Maybe this is slowing the rebuild? Or is it one of the drives? Can I find which one it is?

earth-diagnostics-20190115-1416.zip

Edited January 15, 2019 by snolly

[trurl]

That disk has a pending sector. After the rebuild completes check again to see if it gets reallocated. You should be seeing a SMART warning indicator for that disk on the Dashboard page.

 

After any rebuild I always do a non-correcting parity check to confirm.

 

 

 

 

 

[JorgeB]

3 hours ago, snolly said:

EDIT: Rebuilding is insanely slow. From a few KB/sec to top 2-3 MB/sec. All dockers are shut down, no other activity on the server apart from the disk rebuild. Is there anyway to check what causes the bottleneck? 8 of the drives are on an IT flashed LSI card that has no fan (only heatsink) on it. I read somewhere that this might get hot. Maybe this is slowing the rebuild? Or is it one of the drives? Can I find which one it is?

Everything looks normal on the syslog, possibly a disk with slow sectors, disk5 got disable from a genuine disk error, so while rebuilding on top might fix the pending sector keep an eye on it.

[snolly]

9 minutes ago, trurl said:

That disk has a pending sector. After the rebuild completes check again to see if it gets reallocated. You should be seeing a SMART warning indicator for that disk on the Dashboard page.

 

After any rebuild I always do a non-correcting parity check to confirm.

I cancelled the sync/rebuild it was going at 1MB/sec it would need 2 months to finish. Trying to figure out why the slow speed before I do anything.

 

9 minutes ago, trurl said:

 

 

 

 

 

 

[snolly]

1 minute ago, johnnie.black said:

Everything looks normal on the syslog, possibly a disk with slow sectors, disk5 got disable from a genuine disk error, so while rebuilding on top might fix the pending sector keep an eye on it.

Thanks for the reply. Any way to figure out what's causing the slow rebuild. I cancelled it and installed DiskSpeed container and I will benchmark all drives.

[JorgeB]

1 minute ago, snolly said:

Trying to figure out why the slow speed before I do anything.

Unassign disk5 and do a read check, if speeds still slow one of the other disks could be the problem, if fast likely disk5 is the problem.

[snolly]

4 minutes ago, johnnie.black said:

Unassign disk5 and do a read check, if speeds still slow one of the other disks could be the problem, if fast likely disk5 is the problem.

Alright. I did a test on disk5 and a test on disk3 (same brand/model, same sata controller)

 

Disk 5

 

Disk 3

 

So disk5 seems to be doomed right? Even if SMART doesn't report so. Should I try and do anything with that drive or replace it and recycle it?

 

Regards

[JorgeB]

3 minutes ago, snolly said:

So disk5 seems to be doomed right?

Yes, you should replace it.

[snolly]

Just now, johnnie.black said:

Yes, you should replace it.

OK m8. Cheers for all the help.