System prompted an error message from SMART

[pslleung]

NAS box set up with 5 disks running on raidz, no problem accessing to files.

However, after enabling SMART to run test every 30 minutes, system prompted the following error message every 30 minutes:

"Freenas smartd[9897]: device: /dev/ada1, 3 currently unreadable (pending) sectors"

What's wrong? Do I need to replace the ada1 with another disk? But I read several threads on replacing failure disks and the results seem not encouraging.

Thanks.

 

[jfr2006]

Hi:

I'm having exactly the same issue with 2 discs on my volume1 (in my case, there's 1 currenctly unreadable (pending) sectors).

And i think the cause of this was when i decide to test a self compiled 8r7946 version. It made the discs spin up/down so many times, that the LCC counter has increase till 5300.

And now, for some unknown reason, i'm not able to access my freenas system since middle of this morning...

I'm getting sick of this and i'm on the verge to go back to synology systems. Yes, they are expensive, but at least, all that i had worked without a single problem

 

[joeschmuck]

Hi:

It made the discs spin up/down so many times, that the LCC counter has increase till 5300.

Did you have APM turned on with a value less than 127? This will cause that reaction.

 

[jfr2006]

Hi:

I had, but i have now turn it off and it seems to have gone. But it seems that it only produces efect after a reboot. I had another issue today (temporary power loss and freenas failled to shutdown, even thought it did receive the warning from the ups).

Any way, as a magic pass, it seems the smart error message has gone. Let's hope that's forever!

 

[jfr2006]

Hi:

Any way, as a magic pass, it seems the smart error message has gone. Let's hope that's forever!

I talked to soon.. Still have the error message:

Sep 26 22:23:53 freenas smartd[1585]: Device: /dev/ada0, 1 Currently unreadable (pending) sectors
Sep 26 22:23:56 freenas smartd[1585]: Device: /dev/ada2, 1 Currently unreadable (pending) sectors

Should i get worried about 1 sector?

 

[pslleung]

More errors prompted by SMART as follows:

Sep 27 13:27:06 freenas smartd[3281]: Device: /dev/ada1, 3 Currently unreadable (pending) sectors
Sep 27 13:27:06 freenas smartd[3281]: Device: /dev/ada1, 1 Offline uncorrectable sectors

 

[Milhouse]

I talked to soon.. Still have the error message:

Should i get worried about 1 sector?

I would run the Samsung drive diagnostic utility (or the WD equivalent) against your disk(s) that are showing errors.

Run a full (and non-destructive) scan - this will take 6-12 hours depending on disk capacity - and if it detects errors (which would seem likely) then you should RMA the disks for replacement.

Likewise pslleung, run the drive diagnostic utility from the manufacturer of your disk(s).

 

[pslleung]

I've run the WD utility tool and no exception noted. Currently running HD Tune, the health window indicates 3 unstable sectors and error scan still in progress.

 

[joeschmuck]

I think it's time to temper these SMART errors a bit with this information...

The inability to read some sectors is not always an indication that a drive is about to fail. One way that unreadable sectors may be created, even when the drive is functioning within specification, is through a sudden power failure while the drive is writing. Also, even if the physical disk is damaged at one location, such that a certain sector is unreadable, the disk may be able to use spare space to replace the bad area, so that the sector can be overwritten.

I would recommend reading what SMART is and how it works.

As Milhouse states, run the non-destructive read test on the drive(s) in question. If it fails then you may have an issue. If it passes and you still feel there is a problem you would have to resort to a destructive write/read test which is no fun and takes a considerable amount of time.

My practice is to leave SMART turned off, but that's me. I'm certain others will disagree but that's okay and I'm not saying anyone should do what I do.

 

[jfr2006]

One of my drive heal itself. The other still had a 1 sector pending message. Run samsung ESTOOLS on it, no errors found. Meanwhile, i replaced that drive by a spare WD 2TB i had and it's resilvering. The old one is know under a low level format ;)

Regards.

 

[pslleung]

Error scan using HD Tune Pro revealed nothing, but the 3 unstable sector error message per HD Tune Pro remained. Nonetheless, I sent to the disk to the distributor's service centre and replaced with a new one.

Disk replaced and resilvering done, unfortunately the HD LED remined on so problem not solved, though no more disk error prompted.