First geekblog entry in a while…
At 06.00 Friday (today is Sunday) my Synology NAS started making it’s ‘something’s gone wrong’ beeping sound. I logged on to the admin portal and saw lots of red messages which said, basically, that the Volume was corrupt. I dug a little further and saw two ‘bad sector’ error messages for drive 2.
Accepting a drive failure, but the volume going down really puzzled me because a single drive having an issue should not have brought the whole NAS/Volume down – I have a four-drive NAS with failure/redundancy built in through RAID. About 18 months ago a drive failed and the NAS carried on. While I was waiting for a replacement drive to be delivered, a second drive failed and – unsurprisingly – the NAS just carried right on working.
Anyway, I put this line of though behind me and got on with things. I took an emergency backup onto a 3Tb USB EDD (the NAS backs itself up at 03.00 every morning anyway, I was just being super cautious). Then I replaced the defective drive, formatted it and mounted it into the storage pool. Next I deleted the defective Volume. I installed Synology Hybrid RAID (SHR) with two-drive fault tolerance. Next I created a new Volume. Then I did a consistency check on Volume Root and Volume Swap and on the new storage pool.
Then I installed Hyperbackup and did a full sysconfig-, app-, users-, userconfigs- and data restore which took an overnight job to complete.
Yesterday I ran a bunch of checks on hardware, system, config, and data integrity and everything has come back green. Nothing lost, no problems.
I’m a bit perplexed as to why the RAIDed two-drive fault tolerance didn’t prevent having to rely on backups, but the bottom line is the failure/recovery regime worked.