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HandyMac

macrumors member
Original poster
Sep 27, 2014
62
10
I have a 13" 2014 MacBook Pro with a 1TB SSD, which I've divided into numerous partitions to install several versions of macOS (El Capitan, Sierra, Catalina, Big Sur) and other stuff. I've just installed 10.13 High Sierra on one empty partition, which seemed to go okay. However, after the install, I noticed that the Catalina partition is missing.

It doesn't appear in the Finder, or Startup Manager, or the Startup Disk Preference Pane. Disk Utility doesn't show the partition in the list on its left (see below), so I can't mount it, run First Aid on it, or even erase it. The partition is still shown in the bar graph of the SSD's partitions, but is now titled "disk0s3". (The ghost "disk0s10" on the left is a partition that has Ubuntu installed, and can't be seen by macOS, but at least it's in the list, so could be reformatted if desired.) The Partition panel shows the partition in the pie chart, identified as "disk0s3", Format:Unknown. I could format it there, which of course would erase it (I think, haven't done so yet). Wouldn't be a big loss, I could rebuild it pretty easily.

I did "diskutil list" in Terminal, which shows the partition in the list, identified as "FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF". Kinda weird.

Does anybody have any idea what happened here? Is there some way via Terminal that this partition could be diagnosed and repaired, without erasing it?

disk utility.png
 
Well, if anybody's interested, I did talk with Apple Support about this weirdness. Apparently it was something about APFS, about which I know little. I believe I've read somewhere that the five versions of APFS that have appeared now since High Sierra are somewhat different; perhaps the High Sierra version of APFS didn't like the Catalina version and so screwed up the Catalina partition – though it doesn't seem to have damaged the Big Sur partition on the same drive. Anyway, I eventually tried reformatting the invisible partition, and now it's back, ready to reinstall Catalina.
 
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