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Giuanniello

macrumors 6502a
Original poster
Oct 21, 2012
709
204
Capri - Italy
So, long story short, I have a 750GB HD off a MacBookPro, when I plug it on my ElCapitan MBPro via external dock it doesn't appear in the finder, after a while I get the warning the disk needs to be formatted but the initialization through DiskUtility fails; I did try on another computer with Os10.7 if I recall it correct, there I have the option to change the partition table and there is a small partition which can't be either erased or removed, end of the day the format on 10.7 works but when mounting the disk on the other computer it still isn't utilizable as it is and keeps appearing after a while with the same message which says it needs to be initialized.
I gave it to a friend with a Windows computer and he said he also couldn't format it, nor through the operating system nor during the boot-up with the bios format utility or whatever is that called.

Do you have any suggestion on how to proceed to try to initialize and recover the disk in ElCapitan or whatever any other Os/Software combination?

Thank you
 

Giuanniello

macrumors 6502a
Original poster
Oct 21, 2012
709
204
Capri - Italy
Isn't there anything like what you suggest which works on a mac since I have no more windows machines since 13 years...?

Thanks
 

KALLT

macrumors 603
Sep 23, 2008
5,355
3,375
You can do this in Terminal too (in your applications directory). Use the first command and paste the output here if you like. A disk can be erased completely with the second command (substituting ‘diskX’ with the disk’s identifier).

Code:
diskutil list
diskutil erasedisk jhfs+ name diskX
 

Giuanniello

macrumors 6502a
Original poster
Oct 21, 2012
709
204
Capri - Italy
Same usual problem, it starts the process and after unmounting the disk it doesn't reappear, it's already ten minutes wait and the message is still the same, let's see what happens...

Started erase on disk2

Unmounting disk

Creating the partition map

Waiting for the disks to reappear

[ \ 0%..10%..20%..30%..40%..50%.......................... ] 50% 0:00:04
 

KALLT

macrumors 603
Sep 23, 2008
5,355
3,375
Same usual problem, it starts the process and after unmounting the disk it doesn't reappear, it's already ten minutes wait and the message is still the same, let's see what happens...

Started erase on disk2

Unmounting disk

Creating the partition map

Waiting for the disks to reappear

[ \ 0%..10%..20%..30%..40%..50%.......................... ] 50% 0:00:04

This might also be a hardware problem, i.e. failing hard drive. Do you have any other disks you can try?
 
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NoBoMac

Moderator
Staff member
Jul 1, 2014
5,676
4,247
What KALLT said. Especially in the light that the friend's Windows machine could not format the drive.
 

Giuanniello

macrumors 6502a
Original poster
Oct 21, 2012
709
204
Capri - Italy
So I raise hands and throw it away? Strange thing is that with another MacOs machine with an older OS it is recognized and DiskUtility finds this small partition it can't delete...

By the way, no big deal, I thought to install it into the old Mini and use it to store and stream our music and movie library :-(

Thanks everybody
 

simon lefisch

macrumors 65816
Sep 29, 2014
1,004
253
If you have a Windows machine you can run SeaTools to see if it's failing. I haven't found a Mac counterpart unfortunately.
 

BLUEDOG314

macrumors 6502
Dec 12, 2015
376
120
You can check smart status in terminal, but I am fairly certain if it is connected over USB, smart can't be reported over USB. Try this:

Connect the drive, go to terminal and type diskutil list, then get the identifier, diskX. X is probably 1,2,3 or something, usually 0 will be the internal drive.

Now type diskutil unmountdisk force diskX. It is really important you identified the right number above, next step will nuke anything on the disk.

Assuming it successfully unmounted, type sudo cat /dev/zero > /dev/diskX. terminal should drop down to a blank line indicating it is now writing zeros over the drive. let this run for a second or two, then press ctrl C to stop the process.

Now type diskutil erasedisk jhfs+ name diskX.

Keep in mind if the device does not unmount in the first place, there may be corruption on the drive to the point that once a process like fsck grabs the drive, nothing is usable. in this case, type in diskutil unmountdisk force diskX and leave it in terminal without executing it. Then plug in the drive and quickly press enter. The idea here being to catch the drive and unmount before any processes grab it. Then proceed with the rest of the directions. Just be careful, if you connect any other devices, the drive's disk number will probably change.
 
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