Array has 1 disk with read errors

[gooner_47]

Parity drive has a read error. Diagnostics attached. What's the best course of action?

 

 

nebula-diagnostics-20221101-0718.zip

Edited November 1, 2022 by gooner_47

[JorgeB]

It's logged as a disk error, there's a recent SMART extended test, if it was before the error run another one, if not keep monitoring, but SMART is showing some issues, so probably going to get more errors in the future.

[gooner_47]

Thanks.  The error was after the SMART extended test.  Would it give any useful information to run another extended test now and post more diagnostics?

Should I be looking to replace this drive regardless?

[JorgeB]

Run another test, if it fails replace the disk, if it passes keep monitoring, especially these SMART attributes:

ID# ATTRIBUTE_NAME          FLAGS    VALUE WORST THRESH FAIL RAW_VALUE
  1 Raw_Read_Error_Rate     POSR-K   200   200   051    -    18
200 Multi_Zone_Error_Rate   ---R--   200   200   000    -    1

 

If they keep climbing you will likely get new errors.

[trurl]

2 hours ago, JorgeB said:

keep monitoring, especially these SMART attributes

You should add these custom attributes for monitoring to each WD disk and Unraid will monitor. Click on the disk to get to its settings page

[gooner_47]

"Errors occurred - Check SMART report"  

The report is attached, is this a replacement situation?!  And if so, how urgently does this need to be done?  Not a great time, money-wise, as I'm sure others are experiencing.

Also (and as 6TB is now on the lower end of drive capacity) in the interests of future-proofing - considering the parity drive needs to equal or exceed the largest data drive, and space saving inside the chassis, should I buy as big as I can afford, to allow me to buy bigger data drives than just 6TB going forward?

WDC_WD60EZRX-00MVLB1_WD-WXP1H643RWPX-20221101-1057.txt

Edited November 1, 2022 by gooner_47

[JorgeB]

1 hour ago, gooner_47 said:

is this a replacement situation?! 

Yep, it should be done ASAP since if another disk fails Unraid likely won't be able to rebuild it without errors.

 

1 hour ago, gooner_47 said:

should I buy as big as I can afford

Yes.

[gooner_47]

20TB on the way (thanks credit card!).  Pretty good deal on the WD Elements drives for any UK folks reading - £304.99, works out to £15.25/TB. https://www.amazon.co.uk/Elements-Desktop-External-Hard-Drive/dp/B09TYZCN61/ref=cm_cr_arp_d_product_top?ie=UTF8&th=1

Will this work?

• Turn off machine
• Remove old parity drive and replace with new 20TB on same sata port
• Start machine
• Stop array
• Assign 20TB to parity and let it build

[JorgeB]

Yes, array won't start due to the missing disk, so you can assign it before start.

[gooner_47]

Any general guidance on the best way to check this disk before I shuck it? I'm on mac and have the disk connected via usb still in its enclosure

I've tried WD life guard and it does not find the drive (apparently a common problem)

I've tried smartctl and it says "operation not supported by device" (apparently it can't be used on external drives)

I've seen badblocks recommended very regularly but it seems it was not originally designed for large disk sizes and the -b 4096 flag won't help anymore

I'm aware of Unraid's preclear but I'd need to have shucked the drive first to use that

 

Edit - hmmm, just read about someone who ran badblocks over USB 3 on a 12TB drive and it took about a week.  I only have USB 2 and a 20TB, it sounds like the time taken to do this with it still in the enclosure may be way too long, even if I could get it running.  Should I just shuck it then use preclear in Unraid to check for drive problems?

Edited November 3, 2022 by gooner_47

[JorgeB]

I would just install it in Unraid and sync parity, then run a non correcting check to confirm all is good.

[gooner_47]

Disk is in the case and parity is syncing, eta 2 days.

 

Is this the check you're referring to?

 

[JorgeB]

Nope, run a non correcting parity check after the sync.

[trurl]

2 hours ago, gooner_47 said:

Disk is in the case and parity is syncing

By "case", do you mean the external case for the drive, or do you mean the case of your Unraid server? In other words, did you shuck the drive?

[gooner_47]

29 minutes ago, trurl said:

By "case", do you mean the external case for the drive, or do you mean the case of your Unraid server? In other words, did you shuck the drive?

 

I mean the server/PC case.  I shucked the drive, which Unraid didn't recognise at first, so then I had to tape up the sata pin 3 and it was fine.