I kept getting warnings of disk errors which quickly increased to large numbers:
Disk 2: Previous count: 6112 Current count: 6696
ATA error count has increased in the last day.
Disk 2: Previous count: 36 Current count: 48
Reallocated sector count has increased in the last day.
Disk 6: Previous count: 18176 Current count: 18696
ATA error count has increased in the last day.
Disk 6: Previous count: 86 Current count: 126
So I ordered soem new disks with a view to hot-swapping 2 and 6.
By the time they arrived the NAS was resynching. It went on for days. It got to 85% and then the % stopped increasing. I looked at this forum and decided to reboot. In doing so I decided to have my quotas checked and fixed and checked that option on the reboot menu in Raidar.
Reboot and quota check started. After one working day it is only at 1.3%.
I can't help but think this is being caused by the ailing disk 6.
Thought about rebooting without quota check (before quota check/fix is finished) but I can't access setup in Raidar now that quota check is ongoing. Afraid of breaking something if I use the front panel button to shut down.
You have 2 failing or failed disks, that is the reason the nas did not compete the sync and the quota check failed to progress.
I assume you must have received some prior notification of disk problems, those error counts are huge, it would be unusual for 2 disks to accumulate such high counts acutely. You are also on pretty old firmware - is this intentional?
Anyway, assuming you have no backup and you need to get the data, your best course of action is to contact Netgear support. You will almost certainly need to pay for a data recovery service and they will probably want you to do some disk cloning.
Leave the nas powered off for now as any further fiddling will likely finish things off completely.
It's a bit hard to tell which disk(s) has rising reallocated sectors from your snippet. That drive should definitely be replaced first (and right away).
ATA errors are a bit more slippery, and sometimes can be collateral damage from the main failure. So you could hold off on that one and see if it settles down. Or just replace it both.
The main thing is to back up your data while you still can access it. If you no longer can (and have no backup) then opening a support case makes sense.
Netgear will likely charge for recovery, so you should establish a figure in your mind on how much your data is worth to you. Hopefully you'll stay well below that figure (but its useful to know what is).
A couple more points that might change the approach.
Firstly my six disk RAID has double-redundancy.
Secondly the large error number on disk six is very recent. It started very small recently then went mad.
Thirdly, I have six green lights on RAIDar and until I started the reboot/quota check I could access the volume.
Fourthly, the quota check has advanced overnight to 9.6%.
Fifthly, I have an almost complete backup.
My preference is just to slap in a new disk six, if that is not going to cause damage while the quota check is ongoing, but I don't know whether that is advisable.
...the large error number on disk six is very recent. It started very small recently then went mad.
That's usually been my experience with failing disks. They go very quickly. So I replace them aggressively - the odds that a handful of bad sectors will just stay stable is low enough that I don't want to risk it.
...My preference is just to slap in a new disk six, if that is not going to cause damage while the quota check is ongoing, but I don't know whether that is advisable.
I don't use quotas, so I'm not sure if rebooting will simply terminate the quota check, or if it will restart. If it will just terminate, then reboot is a good idea. Likely the quota check can be killed with ssh also (if you have that enabled).
Is the volume status degraded? If you do have redundancy then perhaps start with just removing disk 6, and see if the quota check runs faster. Your speed issue (and resync failure) might simply be due to the failed disk. That will also give you a chance to assess the ATA situation on disk 2.
