iMac 2012 Won't boot after DP9 Installation

[Aramis]

@Mike

It's the internal 3TB HD that came with the iMac originally.

Claude

https://www.apple.com/support/imac-harddrive-3tb/

[claude]

A GLYPH GPT 50 2TB using the USB 3 Connection.

I tried a trick to make the Recovery HD reappear and now the whole Internal drive has disappeared...

Even if i boot from the GLYPH i can't see the internal Drive anywhere!!

I'm running an extended hardware test as we speak i'll see if the Drive is physically damaged...

Thanks!

Claude

[claude]

Wow Thanks Aramis!

As soon as my Apple Hardware Test(Long) is finished i'll check the serial number.

Hope i'm part of that recall because as i said in my last post, now i can't even see the drive. Even Disk Utility doesn't see it.

Claude

[Aramis]

Wow Thanks Aramis!

As soon as my Apple Hardware Test(Long) is finished i'll check the serial number.

Hope i'm part of that recall because as i said in my last post, now i can't even see the drive. Even Disk Utility doesn't see it.

Claude

Now, I understand it has nothing to do with DP9

I have had no problem with mine yet and I have been able to backup my drive last week in preparation to bring it to Apple next week.

[mikehalloran]

A GLYPH GPT 50 2TB using the USB 3 Connection.

I tried a trick to make the Recovery HD reappear and now the whole Internal drive has disappeared...

Even if i boot from the GLYPH i can't see the internal Drive anywhere!!

I'm running an extended hardware test as we speak i'll see if the Drive is physically damaged...

Thanks!

Claude

Whatever that trick was, not a good idea to do it again.

Disk Utility, possibly run a number of times, should restore your drive. USB, unfortunately, does not support some of the functionality of Disk Utility. Still, run a few times, rebooting in between, DU should be able to bring it back to life.

When Option-Boot didn't show the repair partition, you could have reinstalled the OS while booted into your main drive.

If your HD shows up on the Apple recall list, get it replaced. They will install a fresh version of the OS but will not attempt to restore the data. Do that via Time Machine or Migration Assistant while booted into your internal drive. There is no reason to do a clean install unless it has been many years and you need to get rid of old junk.

[FMiguelez]

That still doesn't make cloning a boot drive a good idea for any reason other than archive.

One should reinstall the OS to create the partition and fix certain issues caused by cloning a boot drive.

Could you please expand a little on that, Mike?

I routinely clone all my boot drives, so if one ever dies in the middle of a project, I simply substitute it for the clone and I'm up and running in 2 minutes. I keep one in the studio and another in my house.

Or did you mean that whatever anomalies the sorce disk has, those will be also cloned? I always repair permissions and disk before doing so to avoid that.

Am I overlooking something?

[mikehalloran]

If you make multiple clones as part of an organized system, nothing wrong that. If one fails, others will work. Get back up and running quickly, of course. When you replace the bad disk as your main boot drive, do it right by installing the OS from scratch, then importing your files as I described elsewhere.

Cloning copies any garbage present in the system. It also ignores any drive anomalies. All drives get bad blocks over time. There are good reasons why Apple never ever recommends cloning. Nothing that SD!, CCC or TTP writes changes any of that.

I am referring to a volume clone, the kind that replaces the contents on the drive.

There are ways of cloning that back up changed files only, similar to normal backup programs and Time Machine. If there's a repair partition on the drive, that will remain untouched.

[mikehalloran]

I clone my VI library drive since there's no reason to include it in a TM backup. Also, I could restore it from scratch if I needed. I keep a copy of the OS and repair utilities on it also.

I prepare such drives by erasing and writing to zeros -- this writes a new partition map around bad blocks. Next I do a volume clone of my VIs drive followed by a fresh install of the OS that also installs a new repair partition. For subsequent clones, I do a file change only. Info this every few months.

My boot drive backs up to three Time Machine drives rotating hourly. They are connected via Ethernet.

[claude]

Well it turns out that my drive is eligible for a free replacement from Apple.

Luckily i did a CCC Clone of the faulty drive. Now i erased everything on it before sending it to an Apple authorized repair place.

What would be the easiest way to get back to business once i get my iMac back? Clone everything back to the new drive? Or maybe i should bite the bullet and reinstall everything?

TIA

Big thanks to Aramis! How did you learn about this recall?

Thanks Mike for your help.

Claude

[mikehalloran]

What would be the easiest way to get back to business once i get my iMac back? Clone everything back to the new drive?

No. That will erase the repair portion.

Use Migration Assistant to pull everything from that clone.

Or maybe i should bite the bullet and reinstall everything?

No reason to do that.