Accidental Mac HD erasure with Disk Utility

9 Apr 2018 22:58:40

Jeanette Jones

Oh dear! I was checking out some Micro SD Cards and trying to format one to work in my Trail Cam and needed to erase it with Disk Utility and somehow everything slowed up and then I realised DU was erasing the Mac Hard drive!!!!!!!

I tried getting out of Disk Utility but obviously couldn’t. The only thing I could think of was to shut the lid to suspend the action and try to get some expert advice.

Hence this heartfelt plea for help, have I reached the point of no return with it?

I have taken a screenshot but I can’t see how to upload the file here.

Jeanette

Re: Accidental Mac HD erasure with Disk Utility

10 Apr 2018 10:04:19

Mick Burrell

Hi Jeanette, a few points for you:

Firstly the good news - Disk Utility will not format the disc it's running from so unless you started from the recovery partition or an external clone, you're safe. If you have started to erase the internal drive, suspending the action won't have helped as you can't tell what has been erased. You'll need to restore from a Time Machine or other backup. By all means email me your screenshot (address on the contact tab).

Whilst it's possible your trail cam uses a Windows format DU can cope with, many of them use their own proprietary format so you'd need to format it in the camera - unless of course you've used DU before so know it works.

Re: Accidental Mac HD erasure with Disk Utility

10 Apr 2018 10:47:27

Jeanette Jones

Thank you Mick, I will email you with the screenshot from yesterday.

I didn’t start from the recovery partition or an external clone, so hopefully, I’ll be safe.
Any idea how I can come out of the state it is in now, so I can get to do a Time Machine backup?

Many thanks.

Re: Accidental Mac HD erasure with Disk Utility

10 Apr 2018 12:14:44

Jeanette Jones

For completeness, I’m putting this info here,
I sent Mick Burrell the screenshot and he replied,
‘Hi Jeanette,
I can't be sure what's happened as the internal disc is shown on the left as APPLE SSD SM05... but DU reports it is erasing Generic SD/MMC/MS PRO Media which sounds like an SD card. However, whilst I'd expect to see the SD card in the list on the left, DU has reported that it's unmounted the one it's erasing so I'm not surprised I can't.

My best guess is that you did indeed select the SD card and that was what was being erased. DU only showed you Macintosh HD as selected after it had unmounted the card.

Try starting the machine. I think it will start and all will be well. if it is, you can try erasing the card again and make sure that's selected in the left hand list and watch to see if it does disappear after DU unmount it.
let me know.
Mick Burrell’

I had indeed taken the SD card out because the Mac stopped doing anything so I thought it had locked up.

Following Mick’s advice, I shut down the Mac by holding down the Power button for 5 seconds, then switched it on again and Phew! it hadn’t erased the Mac Hard drive.
I haven’t tried the SD Card in DU yet as I’m still a bit traumatised as to what might have happened :-/
Very many thanks to Mick for getting me out of this jam.