I decided to upgrade my 2+ years old 6.2.2 firmware to a newer stable one. The latest in 6.4 branch seemed OK -> about 9 months old, so I thought it's been proven. I wasn't wrong, I just missed all the problems others have been reporting...
You know, in work, I'm a responsible sysadmin, reading whole release notes, all procedures, testing all in the lab before trying in production. But at home--well, I'm just a better-class home user. I read release notes for known issues--no such section in Netgear's. So I tried forums, not much there, so I went ahead. Come on, Netgear! How can you expect home users to be able to dig in your KB and/or forums for hours to learn everything they may or may not need for a successful firmware upgrade? I did dig in now, because this now has priority! But before, I had had my kids' homeworks to help with etc. I also do not have another system at home to make tests on...
Now, my system with 5+ TB (4 x 2 TB disks) of data goes into __out_of_memory_390 error about 1 or 2 minutes after I boot it. All the posts here are reiterating one and only solution:
1. Back up the config and all the data (this should be possible even in my situation using "Volume read only" option from Boot menu -> check how-to at http://kb.netgear.com/app/answers/detail/a_id/22891/~/how-do-i-access-the-boot-menu-on-my-readynas-104,-204,-214,-or-314%3F?cid=wmt_netgear_organic).
2. Do a factory reset.
3. Set up the NAS from scratch or restore the config.
4. Restore your data (may be difficult if you use home folders--all individual users need to restore their data themselves as far as I understand it--not even the admin will be able to restore permissions correctly--weird for me, but it's also unconfirmed).
I don't like this kind of solutions, but enough complaining... I only used the NAS as an NFS storage and wasn't using snapshots on the NFS share and wasn't using any other feature. Nevertheless, I believe my problem may be caused by too many snapshots. I believe this article _must_be_ linked to all release notes and firmware upgrade procedures:
http://kb.netgear.com/app/answers/detail/a_id/30033
So far I tried "OS reinstall" from the Boot menu without any success. This morning, I put in a spare 500 GB scratch disk and upgraded firmware to 6.5.0. The machine is running nicely, but my goal is to put in my 4 disks (it'll upgrade the firmware on the disks to what's in the NAS's on-board flash, i.e. 6.5.0) back in this evening in the hope that:-
- either the error will not appear at all, or
- at least I'll have enough time to delete some snapshots before it appears.
If not, I'll try to upgrade to 6.5.1 using the scratch disk and try again. If no success, I'll have to take the system to the work lab in order to backup, factory reset and restore. I've got no other place where I can find 6 TB of space...
I'll let you know my results.
Now I wanted to pass my message to:-
- the community = schedule defrag/scrub/balance of your arrays + disable and delete snapshots if you don't need them + don't trust the vendor that firmware upgrade is painless and risk-free,
- Netgear = no home user is interested in products for which you need 10+ years of IT experience to set up and maintain and 1 working day of documentation research to just upgrade firmware and back up data off it just in case.