# Disk utility problem erasing a large external hard drive



## reid007 (Jan 24, 2007)

I am a Mac newbie so please bear with me with this request for advice. I just bought a Seagate 750 GB (698.6 Gb actual on disk) external firewire/usb drive as a backup device for my Intel iMac which has the same drive internally.
It mounted perfectly and as it came formatted as FAT32 I used disk utility to reformat as MAC OS Extended (Journaled). Mistakenly, in doing this I forgot to change the format, leaving it as MS-DOS. The  erase process completed very quickly and realising my mistake I simply set it up to erase again with the desired format.

The process started but just went on for hours - I thought this might be because it was such a large drive.  After four or so  hours I thought it was hanging - no apparent sound from the drive, so I forced a quit.

I rebooted and reconnected the drive. It gave me the unable to read error, didn't mount and I reopened disk utility to try to erase again to restore things back to a base level. This time I left it for about 21 hours to eliminate any chance it was as a result of the large size of the drive and I had just been impatient previously - still nothing - Disk Utility just appeared to be working away on the erasure.

The drive appears in Disk Utility ok as 698.6 Gb Seagate, the single volume has been renamed (by the system, not me) to disk1s1 and any attempt to erase this volume has the same result.

Beside the spiraling activity indicator is the message : "newfs_hfs: /dev/rdisk1s1: partition size not a multiple of 4k"  In the information below it says Mount Point:  Not mounted; Format Mac OS Extended (Journal) and Capacity 698.6 GB; all other details are empty. No idea whether this is indicative of my problem.

I originally had it daisy chained via other Firewire hard drives and it had mounted perfectly out of the box but I since then have connected directly and swapped cables just to eliminate these as possible sources of problems. I have not tried connecting via USB yet as it obviously is recognised via the firewire connection so I am not sure this is worth it.

Can anyone suggest anything I can do to get this brand new drive operational again? Have I been doing things incorrectly or are there any tricks to recover the process - and are any of my actions so far an absolutely fatal error?

Other than using Disk Utility to erase rewriable DVDs I haven't used it so I'd appreciate any tips you can offer. My search of the posts on this forum seem to indicate that most people have problems where they want to avoid erasure as a solution so they don't lose data - obviosuly not a problem for me here.

Richard
reid007


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## onslaught (Jan 24, 2007)

Seeing as nothing is on the drive, no need to erase it, right? You can rename it (and format) via the 'Partition' tab. If I understand right, you just need to give the hdd a name.


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## DeltaMac (Jan 24, 2007)

reid007 was trying to change the format to MacOS Extended. If the erase or initialization is complete, there's a default name, which is usually Untitled.
The 'disk1s1' is a bsd name and implies a failed partition (among other possibilities)
I would open Disk Utility. Click on the Seagate line, and choose the Partition tab. Change Volume Scheme to something else (1 partition, 2 partitions, etc), and click the partition button. If this completes successfully, click on the Erase tab, and name your partition, change the Volume Format to Mac OS Extended, type something in to name your partition, and click the Erase button. This should complete within a few seconds - 10-15 seconds at the most, unless you have used one of the Security Options. Anything changed there (not needed with a new drive, I would think) will take an enormous amount of time on that 750GB drive. The 35-way wipe would probably take at least a week!
If the partition, or the erase fails to complete within a minute or two, your drive has probably failed. Return for an exchange. Tell them the drive stopped working (which it did!).


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## bookem (Jan 25, 2007)

also check that the partition scheme is set to GUID or APM by clicking the options button under the partition tab in disk utility.


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## reid007 (Jan 25, 2007)

Thanks very much for your input. I have managed to solve my problem. I think the partition solution was the one but I came at it slightly differently. After posting my message I plugged the drive into a PC just to see how it read on a different system - all looked good so I deleted the existing partition, reformatted as NTFS, then reconnected to the Mac and reformatted for the Mac. All worked without a hitch. I'll be more careful next time and thanks so much for the assistance.


reid007


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