Easy Fix for External USB Hard Drives

Read all instructions completely, BEFORE proceeding, because these fixes save your USB hardware, but will probably destroy all the files you have on there. So, (if the files are important to you) find a way to retrieve your files first. Unfortunately, I can't help you with that. Also, I have no idea what "RAID" is; therefore, I don't know how this fix affects that.

Problem(s):
1) cannot allocate memory in Disk Utility message when trying to erase, or initialize.
2) External USB HD won't mount on desktop, but is visible in Disk Utility.
3) upon plugging the USB Hard Drive into the computer, a message appears on the desktop that says something like, the drive you have connected is not readable by this computer, "initialize, ignore, eject"

EASY FIX(S):

Fix 1) If you have access to an external (or internal) Hard Drive which happens to be the exact same GB size as the non-working drive (or SMALLER, because this WON'T work if the broken drive is larger than the working drive), then connect both drives to your Mac

Go to Disk Utility (by clicking 'Initialize,' if that is your error message, or from the finder bar click "Go," then scroll down to "Utility," or double click your computer's internal Hard Drive icon image that is sitting on your desktop to get to the Applications folder that contains a folder that says "Utility" inside of which you will find a gray box with a doctor's stethoscope connected to it - the stethoscope and gray box are the icon for "Disk Utility")
then double click on Disk Utility icon"
once you're in Disk Utility (you should see all hard drives in the column on your left - including the name of the one that won't appear on the desktop), click on the sub-drive image of the working Hard Drive (it appears just below the working drive, but is indented a little to the right)
then click the tab that says "Restore"
drag the working Hard Drive from the left column, to the line that says "Source," DO NOT ACCIDENTALLY PUT THE WORKING DRIVE ON THE WRONG LINE! It goes to the line that says, SOURCE!
drag the name of the broken Hard Drive, from the left column, to the line that says "Destination."
make sure you check the box that says "Erase Destination," then click the button that says "Restore"
after you see the blue bar of progress filling in - at least the width of your pinky fingernail, but no more than halfway, then hit the cancel button.
click on the top tab that says "Erase"
highlight the name of the USB Hard Drive that does not work , then click "Erase."
When it is done erasing, your broken Hard Drive icon will pop up on your desktop already initialized with one partition.
exit Disk Utility, then click on your now fully functional Hard Drive one time to highlight it, then click on "File," then click "Eject."
once your previously broken USB Hard Drive disappears from the desktop, unplug it. WARNING: Do NOT attempt to unplug your working USB Hard Drive (the one that was never broken to begin with) that served as your "Source" drive, UNTIL you "Restart" your computer to make it re-appear on your desktop again, first! Then you can eject it.

Fix 2: For those that have the broken USB external HD "cannot allocate memory" on your Snow Leopard problem, the above steps should work perfectly. However, if they don't, then connect your non-working USB Hard Drive to an older Apple (like a Pismo) that is still running Panther. Go to Disk Utility and use all of the steps above. This is especially workable if you don't have a smaller external Hard Drive, because chances are that your Pismo internal drive IS smaller than your non-working external USB drive.

In the alternative, (meaning you don't have a smaller Internal drive on your older hardware, or a smaller second external Hard Drive),

once you see your broken Hard Drive in the Disk Utility column on the left in an older computer, like a Pismo running Panther,
then highlight the name of the broken USB Hard Drive
click on the tab that says "Erase,"
make sure your "Volume Format" is Mac OS Extended (journaled), then and erase it by clicking "Erase." When it is done erasing, it will pop up on your desktop already initialized and formatted with one partition.

Unfortunately, this fix will not help you with your lost files, but it will repair your non-readable USB external Hard Drive hardware. I did the first fix with an Iomega 320 GB Ego USB Hard Drive. I did the second fix with an I/O Magic 40 GB USB Hard Drive, because the only drive I had smaller than 40 GB was on my 10 GB Pismo running Panther. Neither drive would pop up on any of my desktops.

In Disk Utility, the I/O Magic Hard Drive would NOT drag to the "Destination" line in "Restore," but it did erase on the Pismo. I couldn't get either drive to partition, erase, restore, or appear on the desktop on my Aluminum PowerBook running Tiger, nor my MacBook Pro running Snow Leopard.

Although it took me almost a month to figure this out, for me, this was a far cry better than going to someone's Windows computer to initialize, or buying Firewire enclosures to move my USB Hard Drives into (which may, or may not work). From this day forward, I will NEVER buy another external Hard Drive unless it is both USB and Firewire. Good Luck Little Fish Yaffa