Can't unmount a hard drive

[rtjstevens]

Hi, after saving all the data on an external HD I need to erase/reformat the old HD before reinstalling the saved data. However, I can't do this as Disc Utilities ( and other similar programs) can't unmount the HD.
I've repaired permissions, run TechTool Pro over it, all to no avail. I'd imagine that one possibility is that even when booting from the external HD, it is still using some program/data from the original ... but how do I find out what it's using so I can turn it off?

Thanks

RTJ

 

[TheMonarch]

You want to unmount the HD so you can unplug it right?

I say, just pull the cable out from your computer.

I know, I know, you could get data loss, but unless you unplug it while its is accessing the HD, the chances are very slim.

If its something ultra-super-I'll-die-if-I-lose-it-data, then don't take my advise, but otherwise, you'll more than likely be fine.

 

[rtjstevens]

You want to unmount the HD so you can unplug it right?

I say, just pull the cable out from your computer.

I know, I know, you could get data loss, but unless you unplug it while its is accessing the HD, the chances are very slim.

If its something ultra-super-I'll-die-if-I-lose-it-data, then don't take my advise, but otherwise, you'll more than likely be fine.

The HD I want to unmount is IN the Mac (admittedly connected as the 'slave'. Would you advocate disconnecting it? In which case I still can't unmount it and reformat it again)

Thanks

RTJ