Can the Recovery Disk Assistant make an external hard drive unreadable if you connect it when the Assistant prompts you to connect a USB drive? I did this with an external WD drive that had been working perfectly. Recovery Disk Assistant renamed the drive in the finder window, and presented an error message which said the disk was unreadable, and asked if I wanted to initialize it.
MacBook, OS X Mountain Lion (10.8.4)
It could. Recovery Disk Assistant will restore the built-in recovery drive disk image to the external drive, and thereby rewrite the partition's formatting and all of its contents. If something goes awry in this routine, then the drive can be left in an unreadable state. However, you can likely fix this situation by opening Disk Utility, selecting the drive device, and then in the Partition tab choose "1 Partition" from the drop-down menu. After doing this, click the "Options" button and choose GUID as the partition type, followed by clicking Apply to save the changes. When finished, the drive should be readable again, and you can try using Recovery Disk Assistant again, to mirror the drive.
It could. Recovery Disk Assistant will restore the built-in recovery drive disk image to the external drive, and thereby rewrite the partition's formatting and all of its contents. If something goes awry in this routine, then the drive can be left in an unreadable state. However, you can likely fix this situation by opening Disk Utility, selecting the drive device, and then in the Partition tab choose "1 Partition" from the drop-down menu. After doing this, click the "Options" button and choose GUID as the partition type, followed by clicking Apply to save the changes. When finished, the drive should be readable again, and you can try using Recovery Disk Assistant again, to mirror the drive.
It can. It's always best to back up any data before messing with partitions.
Topher, thanks for the informative reply! Will the partition process erase the data on the external drive? I'm afraid this has happened. I followed the instructions in your post. Disk Utility now lists a new name, "Untitled 1", indented beneath the name of my drive, "1TB WD My Passport". This new item is readable, and can be mounted, but unfortunately the Finder doesn't see any files in it.
My data should still be on the disk, no?
Once you have partitioned, the data is no longer readable. Recovery tools such as DiskWarrior may be able to recover it, but don't hold your breath.
Yes it does. However, by using Recovery Disk Assistant in the first place you wiped the drive, so that process is what both cleared the data and caused your drive to no longer function. The procedure I mentioned also formats the drive, but did so to restore its functionality from your described unusable state, to made it usable again.
Making a drive "usable" again is so easy -- all you have to do is click "initialize" or, thanks to Topher, "partition." Even buying a new drive is cheap. Great! But reading the previous data on the drive - that's a consumation to be wished.
I'm not mad at Topher for suggesting another procedure to wipe my drive. APPLE was wrong not to warn against the danger of merely connecting a USB drive while running Recovery Disk Assistant. Just one little sentence about that could avert disaster.
I realize that one shouldn't do anything with a drive, in any circumstance, without backing up, but I'd never heard that simply connecting a drive could wipe it out. Even so, Apple should have warned that their application can do (will do?) this.
Most of my data is backed up. However, I've added new files and edited old files, and it will take me a long time to determine what's missing and what has been changed.
Sorry to contradict, but it's right there on the installer page:
(Yes, I know this is a Lion one. I'm at a Mac Pro 1,1 which can't run ML)
My bad. Still, APPLE should explain this also on the "About" page that offers the download, for the benefit of inatentive people like me.
Thanks to Daniel & Topher for replies.
Can the Recovery Disk Assistant make an external hard drive unreadable ?
