Disk utility error when erasing an external hard drive

Hi,
Not sure if this is the most appropriate fourm list to post this but I thought I'd give it a try.
I am running snow leopard on my MBP and am trying to use disk utility to erase and format an ext. HD. While the disk icon does not show up on the desktop when I connect it to my mac, Disk utility does show the ext. hd in the left column, but no matter what format I try, even just using one partition and selecting zero out all data, I get the following error: "disk erase failed with the error: POSIX reports: The operation couldn't be completed. Cannot allocate memory".
Is the hd dead? Are there other options? I do have disk warrior, version 4.1.1 and it does not regonize the ext. hd.
Please advise.
Thanks,

Thanks for the reply. Yes, I did select the ext hd as the one I wanted to erase (my internal hd is my start up drive). After I selected the ext hd, (there is no volume listed under it so the only thing I can select is the hd itself). that is when I selected erase and then Mac journaled, then named the hd and then after selecting erase, I got the error. Also as a matter of note, if I select firstaid, both the repair and verify permissions are dimmed, so I can't even try to repair the disk. That is when I tried disk warrior hoping that could examine the hd, but since it is not mounted on the d/t, it doesn't show as a drive to check. I don't understand why the ext hd shows up in disk utility, but not the d/t. Also of note is the fact that when I connect that ext had to my Mac with a fw cable, a window opens saying that the drive is not readable and do I want to initialize it or ignore. I choose to initialize and that is when I get the error. Also of note is that I have tried both security options of "don't erase data" and "zero out data" and still get the same error.
Hope this clarifies things a bit.

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ibond

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ibond

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I have a external hard drive with an iphoto library. I just want to connect my drive and automatically see iphoto open! Possible?
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I haven't had A LOT of experience with external hard drives but enough to get things done. But this problem is a killer.
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Please don't hesitate to ask for more info in order to figure it out. I'll do my best with the knowledge/information I have
Thanks so much!

Read carefully to the end, it is not a long text.
Let us resume the required steps, after putting inside a new, virgin disk:
1. Start up machine and as soon as possible put CD/DVD, press key C to force boot from CD; if the sequence is not fast enough and machine passed over the initial phase, and ? was displayed, force shut down by pressing button key, then start again, with CD/DVD inside
2. Press key C after start, and wait until the Apple logo in displayed, wait
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5. Close Disk Utility and revert to installation proper, proceed.
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So, having recently moved across to Apple, I am now trying to move my data, documents, movie and music files.
I have two external hard drives that I used to use with my PC and now I would like to be able to move things around, and edit the names of folders etc.
I googled for help and discovered that using utilities, I could erase the disks and set them up to be used by both Mac and PC (Still have a desk top at home)...however, when I tried to follow the instructions that I had found. There was an error message stating that the drive could not be unmounted.
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I googled for help and discovered that using utilities, I could erase the disks and set them up to be used by both Mac and PC (Still have a desk top at home)...however, when I tried to follow the instructions that I had found. There was an error message stating that the drive could not be unmounted.
I am currently traveling and would like to be able to use the drive to store the data that I am collecting on the drive (so silly that I didnt check this out before I left home)...does this mean I am completely stuck?
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I used my external hard drive to put on a DMG file for a program and now my external hard drive is acting as a CD.
I wanted to erase the DMG so I could use my external hard drive to put my files on it and use as back up but when I go into disk utilities and click erase it says "Cannot unmount disk."
I'm so confused right now, any help is appreciated.

I finally found the answer!!
If anyone else is wondering how to erase your hard drive after mounting a DMG file on it to use it as an installation disk here's how you do it!
1.Eject the disk from your desktop by clicking on it and then pressing command()+E. DO NOT pull out the cord connecting the external HDD to your computer.
2.Go in to Disk Utility, select the external HD on the left. Note that you cannot select the actual partition, just the HD with the partition.
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PLEASE NOTE THAT FOLLOWING THE ABOVE INSTRUCTIONS WILL DELETE EVERYTHING ON YOUR EXTERNAL HARD DRIVE.

Disk utility error when erasing an external hard drive

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