OS X external drive data recovery

[Markverhyden]

This only applies to OS X. Quick background. Updated a OS X server to 10.9. That went fine. As a precaution, of course, I shutdown all of the external drives attached to it before starting. Once I was done I powered them all up. Two drives, LaCie 2 Big-2 x 500gb-Concatenated Disk Set, did not show up. But all of the lights looked good. After troubleshooting it looks like both of the controllers died. USB shows nothing and Firewire shows an unformatted drive.

These are formatted via a switch selector on the back and was set to Big (Concatenated Disk Set) which is the default. By the way contents of the drives are identical. Started work on the first enclosure. Imaged both with R-Studio, build the array, and then start a scan. Of course this is taking forever since it's happening over USB2SATA.

Started playing around with the first pair of drives on my Retina and the drive with the boot sector shows up in disk utility but the second drive reports no partition. So I grab the second LaCie, pull the drives, hook them up to my Retina. Viola!!! Apple Disk Utility reads the RAID partition and the array mounts properly.

So if you have an HFS+ formatted external drive array that fails and it looks like there is nothing wrong with the drives themselves just try hooking them up to a Mac. If the OEM is not doing something sneaky like some of them with these special adapters that encrypt it should show up. Of course you need to make sure and image each drive before doing anything.

If you have a NTFS/FAT or Linux formatted partition the link below has instructions on how to get this done in those environments.

http://community.spiceworks.com/how_to/show/2399-recovering-data-from-a-lacie-storage-device

 

[altrenda]

Started playing around with the first pair of drives on my Retina and the drive with the boot sector shows up in disk utility but the second drive reports no partition. So I grab the second LaCie, pull the drives, hook them up to my Retina. Viola!!! Apple Disk Utility reads the RAID partition and the array mounts properly.

Sounds like a painful way to recover a drive. Would have been hard for me since I wear glasses.

Many of my customers use the G drives, and 1 had a similar problem where their 8TB drive wasn't being recognized. They called the G drive folks, now Hitachi,and were told to run Disk Warrior. Wouldn't have been my first choice in this instance, but what the heck.

Since they had a backup, I ran Disk Warrior and in less than 30 minutes, the drive was back on the desktop.

 

[trevm999]

Started playing around with the first pair of drives on my Retina and the drive with the boot sector shows up in disk utility but the second drive reports no partition. So I grab the second LaCie, pull the drives, hook them up to my Retina. Viola!!! Apple Disk Utility reads the RAID partition and the array mounts properly.

Wait, so you pulled both drives out then connected them both separately to your macbook and it mounted the array?

 

[Markverhyden]

Used two USB2SATA adapters. OS X's RAID is software based, like mdadm. I'm sure most of these retail level external drives use software based RAID since a real HW based RAID card starts at a few hundred $. So some tools, like mdadm, should be able to be used to re-assemble the arrays. Guess that includes OS X as well.

Read the link I posted at the bottom. Great info.