I have a ReadyNAS NV which has been faithful and terrific for years. I have even upgraded the original disks to Seagate 1TB drives and they have run more or less without fail. Recently ReadyNAS has been reporting a growing number of sector errors on a drive. However, when I put the drive through external testing, both with Seagate tools and Spinrite, the drive always reports as working just fine and no bad sectors are detected. I've rebooted and run volume scans and they never report any errors. I'm running the most current firmware. :( So, what am I to believe? Is it possible something is failing on the device itself and it is reporting errors that aren't really drive errors? Is there anything else I can do on board to test?

What do the SMART statistics say? These are reported by the drive itself. So if the SMART statistics say there are reallocated sectors, then there are. Because the bad sectors have been reallocated, the failures might not have created data loss yet. Also, Seagate tools might still pass, since they use fairly large thresholds for reallocated sectors. However, if you are seeing these rates go, you should replace the drive without delay.

In Smart+ would that be the UDMA CRC Error Count? That in fact does show errors on the drive in question. The Seagate drive is under warranty but I need evidence that it is failing to justify the warranty return. When I have had drives fail before SpinRite found plenty of errors which made it easy to confirm. This time, Spinrite is saying the drive is ok which is why I am a bit perplexed.

jhicks wrote:In Smart+ would that be the UDMA CRC Error Count? That in fact does show errors on the drive in question.I was referring to Reallocated sectors count. UDMA CRC Error Count could be an issue with the drive's SATA circuitry or connector, but it could also be related to the circuitry/connector in the NAS.jhicks wrote: The Seagate drive is under warranty but I need evidence that it is failing to justify the warranty return.Seagate does allow you to return drives that pass seatools, by manually entering codes saying that you know from other tools that the drive is bad. Though with this error, it might be a stretch.How quickly is the count growing?

This has been happening for a while now. I was out of town last week but the log shows On 3/15 a reallocated sector count of 43. 3/17=45, 3/23=53, 3/24=57 and 3/26=63 so definitely increasing. I also finally saw on Smart errors the reallocated sector counts which is of course 63. So I guess my question remains if there is a definitive way to test for bad sectors or if this is a connector issue. This is a relatively old device that is always on in a small/home office setup. I've never been able to find any sort of diagnostic tools other than a volume scan.

If I had 63 reallocated sectors, I would replace the disk. If it is still under warranty Seagate will take the RMA (though you would need to enter a self-service code - I suggest 659DC7AE). Also if you are in the US, you should probably pay them to ship you the replacement first - this is quite inexpensive (not much more than your shipping costs) and it gets you a drive much quicker.

Bad sectors reported but not found

11 Replies

StephenB
Guru
Mar 26, 2012
What do the SMART statistics say? These are reported by the drive itself. So if the SMART statistics say there are reallocated sectors, then there are.

Because the bad sectors have been reallocated, the failures might not have created data loss yet. Also, Seagate tools might still pass, since they use fairly large thresholds for reallocated sectors.

However, if you are seeing these rates go, you should replace the drive without delay.
jhicks
Aspirant
Mar 26, 2012
In Smart+ would that be the UDMA CRC Error Count? That in fact does show errors on the drive in question. The Seagate drive is under warranty but I need evidence that it is failing to justify the warranty return. When I have had drives fail before SpinRite found plenty of errors which made it easy to confirm. This time, Spinrite is saying the drive is ok which is why I am a bit perplexed.
StephenB
Guru
Mar 26, 2012
jhicks wrote:
In Smart+ would that be the UDMA CRC Error Count? That in fact does show errors on the drive in question.
I was referring to Reallocated sectors count. UDMA CRC Error Count could be an issue with the drive's SATA circuitry or connector, but it could also be related to the circuitry/connector in the NAS.
jhicks wrote:
The Seagate drive is under warranty but I need evidence that it is failing to justify the warranty return.
Seagate does allow you to return drives that pass seatools, by manually entering codes saying that you know from other tools that the drive is bad. Though with this error, it might be a stretch.

How quickly is the count growing?
jhicks
Aspirant
Mar 26, 2012
This has been happening for a while now. I was out of town last week but the log shows On 3/15 a reallocated sector count of 43. 3/17=45, 3/23=53, 3/24=57 and 3/26=63 so definitely increasing. I also finally saw on Smart errors the reallocated sector counts which is of course 63. So I guess my question remains if there is a definitive way to test for bad sectors or if this is a connector issue. This is a relatively old device that is always on in a small/home office setup. I've never been able to find any sort of diagnostic tools other than a volume scan.
StephenB
Guru
Mar 26, 2012
If I had 63 reallocated sectors, I would replace the disk.

If it is still under warranty Seagate will take the RMA (though you would need to enter a self-service code - I suggest 659DC7AE). Also if you are in the US, you should probably pay them to ship you the replacement first - this is quite inexpensive (not much more than your shipping costs) and it gets you a drive much quicker.
jhicks
Aspirant
Mar 26, 2012
I've always known I'd have to replace the drive. I guess I was hoping not to have to be bothered with the hassle. But it seems I should just get it over with. Thanks for the help.
gibxxi
Guide
Mar 26, 2012
Just so you know for the future, once a sector is re-allocated, it's essentially invisible to any scanning software. That includes low level tools like SpinRite and SeaTools. The drive itself is substituting one sector (bad) for another (good) internally, and software won't be able to detect this aside from SMART access.

SpinRite's SMART polling is somewhat suspect on newer controllers, quite often saying it can't detect SMART status. Not sure about SeaTools, not used it in a few years.
StephenB
Guru
Mar 26, 2012
gibxxi wrote:
...SpinRite's SMART polling is somewhat suspect on newer controllers, quite often saying it can't detect SMART status. Not sure about SeaTools, not used it in a few years.
Seatools won't show you the SMART parameters from the drive. It does get them, and checks against its thresholds. But Seagate allows more reallocated sectors than I am comfortable with.

Western Digital's LifeGuard will happily show you the SMART parameters from other manufacturer's drives (including Seagate). Acronis Drive Monitor will as well.
gibxxi
Guide
Mar 26, 2012
Is that part of Acronis Disk Director? I've got version 11, but never actually had cause to use it as of yet.
StephenB
Guru
Mar 27, 2012
I am not sure how it relates to disk director. It is a free download from the Acronis site. http://www.acronis.com/homecomputing/pr ... e-monitor/