Author Topic: LS-520D RAID Rebuild Problem - Disk Compatibilty  (Read 121 times)

AlfaMark

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LS-520D RAID Rebuild Problem - Disk Compatibilty
« on: December 23, 2017, 04:29:51 am »
Ok, so I have a disk down in my Linkstation LS520D 2*2TB.

No problem I thought, so searched and order an exact replacement drive a Seagte ST2000DM001 paying 15 more that its newer model the ST2000DM006, as I did not want any compatibility issues.

Anyway the drive turned up and yep you guessed it, I was sent the newer ST2000DM006. I decided to try it and although it was recognised fine, the LS520D had the RAID rebuild button enabled, but upon pressing it, it waited a bit and then it went back to the original screen, without any confirmation that the rebuild was underway.

Checking NAS Navigator, it still reported the RAID was running in Degraded mode and it should have reported I18 - Rebuilding RAID.

I note the newer disk had a later revision of firmware.

I returned the disk.

So word of warning to those in my situation. You seem to need an exact matched pair of disks.
 
I suspect this is a common problem, as by the time the first disk fails, the disk model has been superseded and therefore difficult to get a direct replacement.

Buffalo do have a Disk Compatibility List in PDF for download, however the models listed are now quite old, but they do say most Sata III disks should work, but they cannot guarantee it as they have not directly tested with those.

So I have copied my data to a USB drive for the moment and as I am struggling to get a ST2000DM001.
Knowing the other drive is the same age and therefore also likely to fail soon, I am going to order a pair of new drives and upgrade to a larger capacity (2 *4TB)

I am looking at a pair of Seagate IronWolf 4TB (ST4000VN008) drives. These drive spin at the slower 5900 rpm but are designed for NAS drives and 180 TB/year workloads. They also do a Pro model, but that is another 50 per disk more.

The question is, can any one confirm that these work OK in a Linkstation LS-520D?

Thanks in advance...

gazza040502

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Re: LS-520D RAID Rebuild Problem - Disk Compatibilty
« Reply #1 on: February 21, 2018, 01:58:03 pm »
@AlfaMark - did you actually try to confirm with Buffalo support that those 2 disk models are incompatible in a RAID array? 

Interestingly I have just come across possibly exactly the same issue, I also have a failed ST2000DM001 and was only able to find the ST2000DM006 as a replacement.  I have a LinkStation LS-QVL 4-bay, with the 2 disks in question RAID'ed.  I have managed to get the NAS to recognise the new disk but it still shows with an Error. 

I  was going to back all the data up from the array before I try to rebuild it, but wondering now if that is even going to be worth trying.

Do you still have your old ST2000DM001 (to sell possibly)?  Or interested in my old 1 if I have to go down the path of buying another new version?

Gary.

gazza040502

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Re: LS-520D RAID Rebuild Problem - Disk Compatibilty
« Reply #2 on: February 22, 2018, 01:51:51 am »
As way of an update...

I restarted the NAS again to see if they "Error" status of the new disk would change (it worked for recognising the disk), but no change. 

So after making a copy of the data on the degraded array I initiated a rebuild - the new disk now shows as in Array 2 correctly and the rebuild in in progress.  NasNavigator shows a status as well of "I18 - Rebuilding RAID Array 2...".

I'll leave this for the day to see if the rebuild is successful...

davo

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Re: LS-520D RAID Rebuild Problem - Disk Compatibilty
« Reply #3 on: February 22, 2018, 03:35:35 am »
@AlfaMark - did you actually try to confirm with Buffalo support that those 2 disk models are incompatible in a RAID array? 

Interestingly I have just come across possibly exactly the same issue, I also have a failed ST2000DM001 and was only able to find the ST2000DM006 as a replacement.  I have a LinkStation LS-QVL 4-bay, with the 2 disks in question RAID'ed.  I have managed to get the NAS to recognise the new disk but it still shows with an Error. 

I  was going to back all the data up from the array before I try to rebuild it, but wondering now if that is even going to be worth trying.

Do you still have your old ST2000DM001 (to sell possibly)?  Or interested in my old 1 if I have to go down the path of buying another new version?

Gary.

It's normal that the new disk shows as error until it is built into the RAID array!
PM me for TFTP / Boot Images / LSRecovery.exe file.

gazza040502

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Re: LS-520D RAID Rebuild Problem - Disk Compatibilty
« Reply #4 on: February 22, 2018, 05:05:50 pm »
...the rebuild took around 9 hours! (is that normal for a 2TB RAID 1 array??) but everything is back to a normal state now. 

At the end of the rebuild the main status LED has gone solid blue and all disk lights are green, and the NAS did not need restarting. 

It would have been really nice to have some progress status of the rebuild available during it - e.g. xx% complete. 

Ultimately it would have been nice to understand, as it's not expected, that a single disk failure can bring the whole NAS to a halt, with no details of the cause (maybe there is some better alerting that I need to turn on).  I assumed a NAS should be able to cope with this kind of failure and continue to operate (in a degraded mode) - not require the faulty disk to be physically removed to operate.  Perhaps future versions will get better, or is it a case of getting what you pay for?

In general, very pleased with the product, just a lot of hard work when things do go wrong.