Anyone had this external hard drive problem?

[Poncho]

I installed Mojave on an external drive then booted from this on my Mac as a test to see if Mojave would run some legacy software I need. It doesn't support it. Fair enough.

I then booted my Mac as normal (a fusion drive runnning Sierra) and erased the external drive choosing Mac OS (Journaled) GUID partition. Fair enough.

I then dumped 750GB of data onto this drive, wiped it from my Mac and dismounted the external hard drive.

Today I plug the external hard drive and it doesn't appear on the desktop. I launch Disk Utility, it's listed, and run first aid and get the message: 'First Aid found corruption that needs to be repaired. To repair the startup volume run first aid from recovery. Problems were found with the partition map which might prevent booting'.

Well, firstly, it isn't the startup volume. It's an external hard drive.

Anyway, I booted into recovery mode and tried to repair the drive from there using Disk Utility, but got the same message.

It seems to me that when I installed Mojave on the drive it has changed something deep down in the weeds and now my Mac thinks its a start up drive yet won't show it on the desktop.

So, the external drive shows in Disk Utility (as unformatted, see screen-shot), but no volume showing under the main generic manufacturer's name of the drive.

It doesn't show up in Disk Warrior.

It does Show up in Data Rescue.

Any ideas. I'd rather like my 750GB of data back......

 

[Fishrrman]

"It does Show up in Data Rescue.
Any ideas. I'd rather like my 750GB of data back......"

Since DR can "see" the lost partition, can you do this:
1. Have DR scan the drive
2. If DR finds the files, have it salvage and save them to ANOTHER drive.
3. Does this work?

Just wondering...
Does DR give the option of repairing the drive and restoring the lost partition that way?

 

[treekram]

I don't have any suggestions on data recovery. However, in terms of Mojave breaking your HDD ... the HDD you have (Seagate 7200.11 series) seems to have been current a decade ago. Installing and running a version of macOS, particularly Mojave and particularly if you used APFS, will tax a drive - HDD or SSD (I once did a Sierra install that killed a SSD where people reported similar issues for that model of SSD when it was put under heavy use). So I think if you replicated what you did - with a random selection of old HDD's vs new HDD's with Mojave and then try the same with something like Sierra, you'd find that it's the old HDD's that are causing the problem more so than Mojave.

 

[Poncho]

OK, here's an update.

I looked at the drive in Terminal using 'Diskutil list'.

This showed that though it was Mac OS (Journaled), GUID, it was an APFS drive and not an HFS+. When I installed Mojave on it Mohave obviously changed it to APFS. So I'm trying to read an APFS drive on a Sierra machine, which apparently you can't do. So I installed Mojave on another blank drive. Booted from this then connected the troublesome external hard drive to that. Still no joy.

Then I cloned the troublesome drive to a disk image on another hard drive using Data Rescue 4. When this had finished I couldn't mount the disk image (unsurprisingly). So now I am deep-scanning the the data from the troublesome drive to another external. This worked. Though none of the files have their original names at least I have the data.

Now I'm going to try and change the drive from an APFS one to a HFS+ one using Terminal. Expect it to erase the drive and the data with it, but worth a try. as I have the data back now.

I'm also going to install the Paragon APFS retro-fit kit as this says it allows you to read APFS drives on a Sierra machine.
[doublepost=1549676421][/doublepost]Update. Gave up. Have the data albeit jumbled on another disk so ran the following two commands in Terminal

diskutil apfs deleteContainer /dev/disk3s2

diskutil eraseDisk JHFS+ "Disk_Title" /dev/disk3

Now the original troublesome disk ahs been wiped, is back to HFS+ and is showing on my desktop.

 

[Poncho]

Solution found, so posting it here for any others that one day might find they have a hard drive or thumb drive that will mount on one Mac but not be seen or mount on another. I connected the external hard drive and again it wasn't seen by the Mac, in System Profiler Storage, by Disk Utility or by diskutil list. So unplugged it and launched Console. Again not recognised, but there was a message in Console saying: 'SATSMARTDriver v0.8: disk is not SAT capable'. I found out that this refers to SATSMARTDriver.kext, which is located in /System/Library/Extensions. Went there, chucked the SATSMARTDriver.kext in the trash, turned the external drive off, powered it on, and it mounted!