Fix corrupt NAS files after one drive in RAID volume crashed?

February 19, 2017 3:52 PM

My NAS failed. Now, when I try and copy certain files it either fails or crashes the drive. I have corrupt files--how to fix!?

I have a Synology DS410j NAS, with 3 x 2TB drives and RAID (SHR) single drive fault tolerance. A few days ago, Disk 1 crashed. It failed a Quick SMART test. I replaced it with a new 2TB drive and followed the instructions to remove and rebuild the volume. That failed at some point. Right now, disk 1 isn't listed. Fine--so I've begun copying files to an external drive. (I already had quite a lot of it backed up--just have some newer files to copy.)

I've encountered a couple of issues while copying some of the files:

1. Some files (e.g. 1 small phone video file of 600) give an error "this action is not supported". And then the copy process ends--no matter how many I was copying.

2. Worse. When I copy some other files--a 9GB file, part of my laptop image that I really want!!--disk 3 (which passes a Quick SMART test) crashes. And, since I'm running on just two disks, crashes the volume. When I reboot, the volume comes back up OK--degraded of course because I'm missing disk 1--I can continue to copy other files. But those certain files still cause a crash.

My goal right now is to just get all the files (~1.8TB) onto the external hard drive. I don't mind losing a few music files or family vids etc. But I really want to get my laptop image recovered. Today the NAS sent me a message: Some files have been corrupted because iSCSI LUN of the Disk Group on Synology410j has failed. Files are at the risk of being damaged under the degraded mode.

Any suggestions to fix these? (I still have the original disk 1--although I've since moved some files around.) I found this page, which suggests SSHing in and using e2fsck -pvf -C 0 /dev/vg1/lv to fix files.

Thanks for any help!

posted by NailsTheCat to Computers & Internet (4 answers total)

I am sorry to see that nobody can assist you. Have you contacted Synology for their advice? I haven't dealt with their customer support, but I am a customer since a while. So far so good, in my case.

For anyone reading this, even with a NAS with a fault tolerant RAID array, it is of utmost importance to frequently backup your data to a different hard drive, and then to even store it outside of your home. (Burglary, natural catastrophes)
posted by nostrada at 2:38 PM on February 20, 2017

Response by poster: Thanks for the response nostrada. Yes -- I wrote to Synology on Saturday, no news yet. (Well, it's a holiday weekend--if it's US support so perhaps I'll get something later in the week.) Fortunately I had a weekly back up running for the lion's share. It's just a few folders that weren't backed up including my laptop snapshot. Doh!
posted by NailsTheCat at 8:19 PM on February 20, 2017

I don't know Synology at all, but have you tried this?

https://www.synology.com/en-global/knowledgebase/DSM/help/DSM/StorageManager/volume_diskgroup_repair


It was the first hit when I googled "synology fix corrupt"
posted by Diag at 4:12 AM on February 22, 2017

Response by poster: Thanks for the reply, Diag. Yes, that's how the volume is rebuilt. The issue I have is that it cannot read certain files / sectors. I didn't mention it in my post but when I try and rebuild the volume, it crashes--because it can't read those files I expect. I'm working with Synology support who are reviewing my logs. It doesn't seem likely anything can be done now but... I've already had to rebuild my laptop separately anyway--so it is what it is...
posted by NailsTheCat at 5:29 PM on March 4, 2017