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Kernel Panic/Reset on Import

Posted: 19 Jan 2015 19:21
by hdantman
Firstly, please let me thank you all for your work on this distribution! It's excellent, and I believe head and shoulders above the competition, and I've used them all (ZFSGuru, OpenMediaVault, FreeNAS, OmniOS, and OpenIndiana with Napp-It).

I'm very new to the forums, but I've been using ZFS on the above distros for about 4 years now, so I thought I was familiar enough with it. Until now.

I have a 6-drive RAIDZ2 with 3TB Seagate drives, 32GB ECC RAM, a Supermicro X10SL7-F-O motherboard, and an Intel 1230 V3. Right now, Nas4Free is running in a Virtualbox VM hosted by Server 2008 R2, though it was running on bare metal before I had the problems listed below. I put it in a VM to see if I could get any other distro to successfully import my pool so I could back it up.

That's key. Back it up. The pool was serving as a backup for a lot of data. About 3TB worth. I assumed RAIDZ2 would provide me with reliable storage that I could use on battery backed-up server hardware and simply not worry about it. I was wrong. I will never make the same mistake again, and will back up everything to another array. The problem is, I need a lot of this data. I have tax year 2014/2013 data that's very important, and photos that are irreplaceable.

So, all that said, I get a kernel panic on every single FreeBSD/Oracle/Linux-based ZFS Zpool import command I run, with the exception of zpool import -f -N -o readonly=on storage (storage is the name of my pool). I am able to import it read-only on Nas4Free, but when I browse to the share I create, there is nothing in it (it doesn't actually browse to that share, it shows the Nas4Free install directories instead). I don't know enough to change the mount points to see if perhaps it's simply mounted improperly, so it is mounted to / .

I'm at a loss here. I can't imagine what could have happened to a healthy pool overnight that would cause it to crash what are known to be rock-solid operating systems. The pool shows up as Healthy, and I've tested the disks. Everything appears to be fine until I zpool import storage.

FYI, on the hunch that it could be bad hardware, I replaced the entire server with new hardware, with the exception of the drives. I have 3 additional identical 3TB drives, one of which I removed from the array a few months ago when I was getting some errors on it.

Is there any known way to pull data off the drives? I know there's redundancy here, but without mounting/importing the pool, I don't know how to get at it.

I'm grateful for any help you guys can offer me. Please let me know if you need any additional info to formulate a response. Thanks again!

Re: Kernel Panic/Reset on Import

Posted: 19 Jan 2015 19:52
by hdantman
How would I set the zfs_recover 1 option in NAS4Free? I'd like to run a zdb -e -bcsvL and see if it helps. I'm really trying anything at this point. I've been working on this for the past month. I probably should have asked for help much sooner.

Re: Kernel Panic/Reset on Import

Posted: 19 Jan 2015 20:25
by hdantman
I'm currently the happiest man on this planet. Apparently all I needed to do was post this here to get an instant fix! Here's how I did it:

1.) from shell, did an zpool import -F -f -o readonly=on -R /mnt/temp storage
2.) set up Samba in the web GUI of NAS4Free, and set up a user with permission to access it that defaulted to the directory where I mounted the share (/mnt/temp)
3.) browsed to the share on the network.
4.) Viola! My data is back! I'll never make this mistake again. I hope this helps someone. I've been working on this for over a month now with no success. Until now.