Access data on external drive after installing OS on it?

[vsea]

Hi! I installed Big Sur onto my external drive, because I didn't have enough space on my laptop and honestly I guess I didn't really know what it meant to install to an external drive. Now I am unable to access all the data that I had previously stored on my external drive - basically, all the documents, photos, etc that I have ever had. It appears as though the data is still there - when I go to Disk Utility, it shows 275 GB of "data" on the external drive which is about right for all my stuff, plus 15 GB of "other volume" which I'm guessing is the OS.

The data doesn't show up like it usually does on the Finder sidebar, and when I unplug the external drive and reboot with Catalina, it won't let me access the external drive at all.

Any suggestions? I don't need to keep Big Sur on the external drive, but I don't know how to get rid of it without deleting all my important files. Thanks!

 

[Josef Law]

Enable and use the root user account.

 

[vsea]

Enable and use the root user account.

Okay, I logged on as root ... still can't access the data portion of the drive. This is what Disk Utility looks like... I think the files I need to access are in the "data" portion (I hope), but I can't figure out how to get at it.

 

[Nukeban]

Sorry to ask, but if you don't need Big Sur, why did you install it? Not trying to be nasty, just suggesting that one theory is that it's best to avoid new versions of _anything_ unless we have some specific reason for doing so. New and free isn't a good enough reason, imho.

I'm particularly wary of new versions of Mac OS, both because like any OS it's central to the computer, and because Apple is always "improving" things in a manner that can lead to confusion.

When I do install any new version of Mac OS I do so from scratch on an empty drive, and then gradually install my apps and data. That is, I don't touch my working boot drive until I know for sure the new setup works like I want it to.

My apologies if none of this is relevant to your situation, and sorry I can't be more helpful with this specific situation.

 

[vsea]

I need to use iMovie for work, and it wouldn't download unless I had Big Sur. I've never had a problem updating my OS before so had no reason to think it would be an issue. I just had no idea that it would make the rest of my external drive inaccessible.

 

[vsea]

I've been chatting with Apple Support for hours - tried logging in in Safe mode, unmounting and remounting the drive, and plugging the external drive into a PC, no luck. They think the data is unrecoverable. I know everyone's probably laughing at the dumb lady installing an OS onto a drive with important files on it, but I honestly figured it would ask for permission before deleting anything. Just crushed.

 

[TonyAguila]

I think I know what heppened. Before you installed Big Sur on the attached drive, it was formatted HFS+, but in order to install macOS 11 Big Sur, the drive needed to be reformatted to APFS. This means a complete wipe of the disk. If you don’t have a clone or Time Machine backup of the drive before installing Big Sur, I’m afraid all of you previous data is gone. If you do have a Time Machine backup, then all you need to do is run Migration Assistant with the Time Machine drive also connected.

Unless you are certain that the drive was APFS formatted to begin with, my guess is that it was an HFS+ partition, which had to be deleted before the APFS changeover. Apple Support should have known this right away.

P.S. I’m not laughing.

 

[Nukeban]

I need to use iMovie for work, and it wouldn't download unless I had Big Sur. I've never had a problem updating my OS before so had no reason to think it would be an issue. I just had no idea that it would make the rest of my external drive inaccessible.

I hear your pain. You are not alone. In the 25 years I've been using Macs I've read at least a thousand threads from folks having OSX upgrade calamities.

This won't solve the current issue, but have you tried Hitfilm Express? It's a free video editor for Windows and Mac (they also have a paid professional version). I'm using an old version of the free software, and it meets all my needs.

I used iMovie years ago, back when everybody loved it. But when Apple "improved" iMovie I bailed (along with many others) and wound up with Hitfilm.

Learning a new video editor may not be appealing at the moment, but perhaps it would be helpful to at least know it's there, if you don't already. They have a very helpful forum which was essential to me when I was getting started with Hitfilm.

I haven't used iMovie in years now, so I can't really compare it to Hitfilm or any other video editor.