Lacie 2Big NAS–Recovering Data with Good Drives/Bad Device

Today, my faithful Lacie 2Big NAS box which has served me reasonably well for a number of years had a bit of a problem.

The box is a simple device which in my case has 2x500GB hard drives in it and runs them in a mirrored (RAID1) configuration so that if a drive fails you simply take it out, drop in another one and it rebuilds the mirrored set for you.

Actually, that’s the dream. When I did have a drive fail, I found that I had to send the failed drive back to Lacie who then sent me a replacement so it’s still pretty good but not quite as simple as it seems. Following today’s investigations, I suspect that I could now sort that out myself.

The box has a number of status indicators on it and, specifically, at the back it has 2 lights which indicate drive health and a big on on the front which indicates “general health”. There’s a description of these lights on the Lacie website;

which reads;

The LED indicators above the drive bays and the front LED indicate drive status and activity.

During Startup
  • Front LED – blinks red/blue until both disks are powered on, then turns solid blue.
  • Rear LEDs – blinks red/blue until corresponding disk is powered on, then turns solid blue.

NOTE: If the device is not able to initiate the boot process following disk startup, the front is solid red.

During Bootup
  • Front LED – solid blue
  • Rear LEDs – solid blue

NOTE: If a disk is failing, both the disk’s corresponding rear LED and the front LED will be solid red.

During RAID Synchronization
  • Front LED – solid red
  • Rear LEDs – The LED corresponding to the original disk will be blinking blue and the one being synchronized is blinking red
  • Once both disks are synchronized, their corresponding rear LED and the front LED will be solid blue

Now, my particular problem didn’t seem to be well described by any of these in that my device didn’t seem to be starting up properly but the light indicators were as follows;

  • drive bay 1 – solid blue light
  • drive bay 2 – flashing blue light
  • front LED – off

and nowhere on the Lacie site do you get a description of what that might mean.

I’ve a suspicion that it’s perhaps the power supply that has broken or possibly it’s something inside the NAS device itself and so I sent off for a replacement power supply to see if that fixes the issue.

I suspected that the disks might be ok but I started to worry a little about getting the data off the drives even though I had a fairly recent backup of the data I still didn’t really want to consider the delta between the backup and the actual data on these 2 mirrored drives.

It’s at this point when I started to question whether it’d been wise to stick with this simple Lacie device for all these years as I realised that I had no idea how the data was actually stored on the drives and I began to figure that getting to it might not be as simple as I might hope for.

I stuck the 2 drives into an old desktop PC and took a look at the partitions on them and spotted pretty quickly that each disk looked pretty much identical and seemed to contain a 464MB partition which I suspected contained my data along with a bunch of other partitions.

I hunted around a little for a way of mounting the filesystem from that partition on a Windows box (I tried both this Ext2 installable driver and this Ext2Fsd driver) before coming to the conclusion that while some of the partitions on these drives were either in EXT2/EXT3 the actual data that I was looking for wasn't.

Given that it was a Linux box that stored this data, I gave up trying to use Windows to read it at this point and decided I’d try and use Linux to read it and settled for Ubuntu.

At this point, I struck pure Gold because I found this post;

The Great Lacie 1TB Big Disk Recovery Experiment 

which had almost the exact details of how to go about it albeit with a slightly different device. The particular steps that I followed were;

  1. Took all disks out of my desktop PC.
  2. Installed the 2 disks from my Lacie 2Big NAS into my desktop PC.
  3. Downloaded an ISO installation of the latest Ubuntu version.
  4. Installed that onto a USB key.
  5. Booted my desktop PC from that Ubuntu installation on the USB key (letting Ubuntu run from the USB key rather than actually installing it).

Once I had Ubuntu running, I followed the steps outlined in the original post although I think anyone armed with a little Unix history and man mdadm would be able to figure it out from this point in.

I used the GParted partition editor and managed to locate my 2 disks (/dev/sda and /dev/sdb for me) which contained the 2 partitions that made up the mirrored set. For me, these 2 partitions were called /dev/sda2 and /dev/sdb2 and were easy to identify because they showed up as 464GB partitions (labelled as XFS in the tool).

With those identified I installed mdadm by doing a;

app-get install mdadm

which seemed to work fine and then I did a;

mdadm –-query /dev/sda2

as detailed in the original post which told me that the device I was looking for was /dev/md4 and with that in place I could re-assemble the mirrored pair;

mdadm –A /dev/md4 /dev/sda2 /dev/sdb2

Now, at this point I got puzzled for a while because the original post suggested that this was all I’d need to do to access the filesystem but that turned out not to be the case for me. I still had to mount it. I found that I could check the status of the mirror by doing a quick;

mdadm –detail /dev/md4

and that looked promising because it gave a nice description of the 2 volumes and told me that they were clean and then finally I figured (by trying mount) that the filesystem wasn’t mounted and so did something along the lines of;

mount /dev/md4 /home/ubuntu/lacie

and then I found that I could see my data at /home/ubuntu/lacie and so I just stuck another USB drive into the desktop PC and started copying the data off there.

And with that all done – I think I’ve got my data back Smile For me, I’m going to have a think about whether I trust this device to manage my files in the future given that it’s storing data in a fairly opaque way which can make it a little tricky to retrieve if something goes wrong. It’s also quite an old device so maybe it’s time for a rethink.

I hope if you come across this post via a web search then it’s useful to you and that you also get your data back too Smile