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4sallypat

macrumors 601
Original poster
Sep 16, 2016
4,034
3,782
So Calif
Stuck here: a clean installation of Catalina onto a 2012 MBA which has a 64GB SSD which I am listing on eBay to sell.

The MBA had previously been on High Sierra and after booting from a USB Catalina boot disk, Disk Utility reports 2 identical sized volumes. One says "Macintosh HD" the other says "Macintosh HD - Data"

They are being erased for APFS volumes.

When I try to install Catalina, I get a choice between 2 drives - both 64GB

Anyone know why this is happening and which to choose for the OSX installation ?
4dbd64.jpg
 

revmacian

macrumors 68000
Oct 20, 2018
1,745
1,468
USA
I'm on a 2019 MacBook Air running macOS Catalina 10.15.2 and I only see 1 HD on my desktop, labeled "Macintosh HD". I upgraded from Mojave (no clean install).

From what I understand, the drive labeled "Macintosh HD - Data" is normal for Catalina.
 
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4sallypat

macrumors 601
Original poster
Sep 16, 2016
4,034
3,782
So Calif
Thanks all for your wonderful assistance!

I found this:
By doing an UPGRADE from High Sierra to Catalina, there is only 1 drive that shows (like normal).

And doing a full CLEAN install (USB Boot) to Catalina results in 2 drives.


Interesting ......
 
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Thanks all for your wonderful assistance!

I found this:
By doing an UPGRADE from High Sierra to Catalina, there is only 1 drive that shows (like normal).

And doing a full CLEAN install (USB Boot) to Catalina results in 2 drives.


Interesting ......
Myself, I did a fresh, clean installation of OS 10.15.2 from an external SSD containing a SuperDuper! bootable backup, not from a Flash Drive. But I suspect that should make no difference.

Also, I can only "see" the two volumes via Disk Utility. Only one of them shows up on the desktop after booting either of my Macs.
 

gilby101

macrumors 68030
Mar 17, 2010
2,950
1,634
Tasmania
Is this normal ?

No it is not. Unless you look with Disk Utility, you should only 'see' the combined disk Macintosh HD.

Do the install again, by booting to recovery mode (or from a USB install disk), erase the whole disk using Disk Utility and then install.
 
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IowaLynn

macrumors 68020
Feb 22, 2015
2,145
589
Sounds like the conversion of the system cluster still left a blessed system on the - Data volume.

I assume using Startup Disk to set - Data as bout volume will fail.
 
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No it is not. Unless you look with Disk Utility, you should only 'see' the combined disk Macintosh HD.

Do the install again, by booting to recovery mode (or from a USB install disk), erase the whole disk using Disk Utility and then install.
You can also "see" both of them when one runs EtreCheck. I just did it. And yes, I can also see both of them with Disk Utility.

From what I remember, both of them will appear on the desktop if I boot my machine from its SuperDuper! backup on my external SSD. That desktop, of course, "belongs" to the backup volume.
 

Peadogie

macrumors regular
Aug 4, 2019
223
145
Georgia, USA
@4sallypat, can you boot your MBA? if so post a screenshot of your drive from Disc Utility (click on the view button and choose Show All Devices). it should look something like this (my drive is named Catalina):
Screen Shot 2019-12-22 at 8.51.36 AM.png

If you can't boot your MBA I would follow the advice gilby101 posted.
 
Their blog says 11/26/19.
Yes, that was the date.
When did SuperDuper get the ok for Catalina?
One can enter the search term SuperDuper! in your browser's address line, and you'll get this (assuming you are using Google as your search engine):


Then, clicking on the first link brings up this:


That is what I kept doing.

You can also click on Check for Update... under the SuperDuper! heading after launching it.
 
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IowaLynn

macrumors 68020
Feb 22, 2015
2,145
589
I was holding off if SD! and happy with CCC. Hadn't seen or read anything especially here. And maybe a month is enough time for issues never dreamed of from surfacing, like the OP has.
 
I was holding off if SD! and happy with CCC. Hadn't seen or read anything especially here. And maybe a month is enough time for issues never dreamed of from surfacing, like the OP has.
I actually made a post about that new version on November 26th:


Also, it is now at version 3.3.1, but everything is working fine. I have been using the new version for my past 2 backups: a week and a half ago with both of my Mojave-based Macs, and yesterday with my Catalina-based Mac Book Air.
 
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