Missing partition in external disk

[pdmateus]

Long story (maybe someone can point me in the right direction as I'm a macOs noob.

I have an old 3TB external disk that I used for a few things (backups mostly), and for some reason one of the partitions is on HFS Plus (it says:Mac OS Expanded (with journaling) ) and the other one I don't remember (maybe APFS or exFat?).

My iMac had macOS High Sierra and I used OpenCore legacy patcher to upgrade my 2011 iMac to Monterey, all went fine but in the meantime I noticed that missing partition...

My HFS Plus/timemachine partition is all good and checked but the disk, if I show all devices and do first aid it fails, error fixing partition map, not possible change mapping -69874, and from what I read they all metion bootint into recovery.

Reading this: https://forums.macrumors.com/threads/partition-disk-disappeared.2234920/, I start to think that missing partition is on: HFS+, with some suggestions to go to Recovery or Internet Recovery and try to fix it.

Problem is, when I select recovery boot in OpenCore Legacy Patcher, I get a black screen and I can't do anything...

All others seem to work fine, openshell etc.. (I still boot from USB not sure if that's the reason)

Any ideas?

 

[joevt]

Try booting installer instead of recovery since they basically have the same tools?

 

[Fishrrman]

Try the 3tb external drive on a newer Mac running a newer version of the OS.

What was ON the "other partition"?
Was it bootable? At least previously?

 

[pdmateus]

Yesterday I was tired, not thinking straight lol Tks for your replies!

But still, today I tried on my mbook air m1 with sonoma, recovery>disk utility same issue.

this other partition had just files, it was not bootable.

I ran diskdrill that I had a trial and it shows the missing 1TB in RAW, many missing filenames apparently, but it does show my data... but its the trial, and lots of missing filenames, file01 02 03 etc.

I still don't know for sure what FS it has...

Any ideas?

And does anyone recommend a good recovery tool?

 

[joevt]

If it's HFS+ then Disk Warrior is what I would use.

Maybe gather more info first. Try my dumpvols.sh script: https://gist.github.com/joevt/a99e3af71343d8242e0078ab4af39b6c

 

[Fishrrman]

"I ran diskdrill that I had a trial and it shows the missing 1TB in RAW, many missing filenames apparently, but it does show my data... but its the trial, and lots of missing filenames, file01 02 03 etc."

The fact that diskdrill is showing data (even if it can't show original file names) indicates that there could be directory damage (which would prevent the partition from mounting).

Does diskdrill allow you to recover one file to see if "recovery" is possible?

Be aware that with data recovery software, even if you can get "the data" back, you might not get the file names that were originally associated with the data. Remember, you're recovering from what may be a damaged directory.

You also are going to need ANOTHER drive that is large enough to hold all the data on the damaged drive. You can't "recover" to the damaged drive.

I'm going to GUESS that if diskdrill can recover the data, what you're going to end up with is a drive with a lot of "numbered files" but WITHOUT the original file names.

This is often "all you get" with data recovery.
The point is, even without the file names, you GOT THE DATA BACK.
It may take quite a while to "rebuild" by examining and re-naming each file.

Then again, some files may be recovered WITH the file names.

You won't know until you try it.

Hmmm...
as JoeVT suggests, you might try DiskWarrior FIRST, to see if the directory can be rebuilt.