LS-Q4.0: suddenly stopped working with "disk cannot be mounted" message

[ahopper]

I have a LinkStation that has been working perfectly until the last couple of months. Recently, it started shutting down. I had thought it was due to the "automatic shutdown on error" setting, but I've had it running weekly scans for years with no error reports. In addition, after running a disk scan no errors were found. However, this weekend it failed to start up with the blink code (e22) and a bazillion emails stating that "Disk cannot be mounted" but that it was an unknown drive. I've tried replacing drives 1, 2 and 4 with a new 1TB drive (just haven't gotten to 3 yet). I did see one weird symptom; after swapping out drive 1, I got an error email starting that it cannot mount drive 4, and that's the latest drive I've tried swapping out.

Is there anyway to mount these drives on a computer? I reeeeeeally need to get these baby pictures off of this NAS or my marriage just might be at risk.

[davo]

Unknown disk usually means a USB disk, do you have any USB devices connected?

[ahopper]

No, only the inbuilt SATA disks.

[davo]

So you're saying you have replaced 3 disks already?! What raid mode were you using? What errors does the NAS navigator say? If you have replaced 3 disks since you got the errors then your data is probably already gone.

[ahopper]

Sorry if I wasn't clear. I have not swapped out three disks total; I have a replacement drive, and I've tried putting it in drive bay 1 (turn on, wait, get error), then replace the original in drive bay 1 and try the new drive in drive bay 2 (turn on, wait, get error), etc. At present, all 4 original drives are in the unit. It turns on, indicates that it's checking drive 1 in the NAS navigator, and after a very long period (we're talking > 12 hours) proceeds to spam me with the "Disk cannot be mounted" emails.

[ahopper]

Oh, and it's in the default  configuration (one big RAID5 array).

[Eastmarch]

Shut the unit down and try to reboot it with drives 2,3, and 4. If data is accessible, back up immediately!

If not, then try drives 1,3,4 ; 1,2,4; and 1,2,3. At any point if data becomes readable, back it up.

You are attempting to isolate the bad drive and boot without it. if none of this enables you to read data, I have bad news for you, you have likely lost more than one drive, or the drive failed in such a way as to damage the array.

At that point you have to decide if professional data recovery is worth the cost.

Once you have decided by hook or crook to move forward, you -really- need to build a backup strategy that will prevent this sort of issue in the future. A real backup doesn't share a single point of failure with the master copy. In this case, the array is a shard failure point.

I wish you the best of luck.

[ahopper]

Well, the good news is that the unit boots with drive 1 removed. However, while it's letting me see the shares (info/share/Backups/lpt), I can't access them. If I go to RAID configuration, it's showing that a RAID error has occurred. If I put the new drive in slot 1, will it be safe to restructure the RAID to include this drive, or will that whack the data in the array? Sorry for the newbie questions; in 25 years of using various RAID arrays at work and home, this is the very first time I've ever actually had one fail out from under me!

[ahopper]

OK, after RTFM I found that restructuring is fairly simple. I have inserted the replacement drive waited for the system to spin up, and clicked the Restructure button.

However, now I'm in a weird place: I received a message stating that the restructure was successful, but nothing is available. If I look under Disk Management -> Drive Properties I see that RAID Array 1 claims to be "Not Configured."

In addition, NAS Navigator is showing the NAS with a yellow warning shield with a message like (this changes over time):
Error:
E22: Cannot mount drive 4. (2016/03/29 22:59:52)
Status:
I18: Rebuilding RAID array 1... (2016/03/29 20:16:26)

Every 10-15 minutes the unit seems to go through a soft-reboot; the HDD lights all turn orange and eventually come back to green, and every so often the list of drives reported with the E22 header changes. The only things that has been constant is the I18 message.

At this point, I'm hoping that the E22 errors are red herrings reported during a rebuild, and that the I18 is reporting the current status (and not just an old message). It has only been a couple of hours, so I will be patient and see how things look in the AM.

[ahopper]

The RAID rebuild appears to have completed, but we're right back to the original issue. The system boots, all the HDD lights turn green, but I'm getting LED error E22 and tons of emails stating:
DISK Error Notification

HDD error occurred
Disk(s) the error occurred
:UnknownDisk()

Disk cannot be mounted.

In addition, if I log into the Web UI, I see a message saying "back fan malfunction" - but I see the fan is spinning.

I am by no means a Buffalo expert, but I'm starting to wonder if it's the controller. Is there a LiveCD that I can run that would allow me to attach these drives to a computer and perform diagnostics/recovery? Does anyone know anything about the default configuration and how one would rebuild it on a computer?