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I was setting up an external SSD for my son who has a new 20202 MacBook Pro with Big Sur. I used Disk Utility to "erase" the drive, selecting APFS and GUID Partition. Now when I eject it from Finder I get the following:
What's the deal? If I were to format a drive this way on my High Sierra Mac, then use it on his mac, would that work? Would it only have one volume? Thanks.
MacBook Pro (2020 and later)
Alfredo Jahn wrote:
Just to add... I'm trying to figure out if this is a Big Sur thing or not. On my High Sierra MBP, erasing (formatting) an external SSD shows up as a single volume. If I try to eject it, it doesn't indicate more than one volume. When I did this on my son's new 2020 MBP, it shows up as 2 volumes.
I just realized something. I used this external to clone from the internal HD. Now I'm wondering if using Carbon Copy Cloner may have changed the formatting to accommodate the Big Sur internal HD...
Your old macOS High Sierra is not the new macOS.
ref: About the read-only system volume in macOS Catalina - Apple ...
https://support.apple.com/en-us/HT210650
This continues today with Big Sur adding a Signed/Sealed System Volume— as well as Monterey.
I would just click to Eject All. This is not an issue.
Alfredo Jahn wrote:
Just to add... I'm trying to figure out if this is a Big Sur thing or not. On my High Sierra MBP, erasing (formatting) an external SSD shows up as a single volume. If I try to eject it, it doesn't indicate more than one volume. When I did this on my son's new 2020 MBP, it shows up as 2 volumes.
I just realized something. I used this external to clone from the internal HD. Now I'm wondering if using Carbon Copy Cloner may have changed the formatting to accommodate the Big Sur internal HD...
Your old macOS High Sierra is not the new macOS.
ref: About the read-only system volume in macOS Catalina - Apple ...
https://support.apple.com/en-us/HT210650
This continues today with Big Sur adding a Signed/Sealed System Volume— as well as Monterey.
I would just click to Eject All. This is not an issue.
leroydouglas wrote:
Alfredo Jahn wrote:
Just to add... I'm trying to figure out if this is a Big Sur thing or not. On my High Sierra MBP, erasing (formatting) an external SSD shows up as a single volume. If I try to eject it, it doesn't indicate more than one volume. When I did this on my son's new 2020 MBP, it shows up as 2 volumes.
I just realized something. I used this external to clone from the internal HD. Now I'm wondering if using Carbon Copy Cloner may have changed the formatting to accommodate the Big Sur internal HD...
Your old macOS High Sierra is not the new macOS.
ref: About the read-only system volume in macOS Catalina - Apple ...
https://support.apple.com/en-us/HT210650
https://discussions.apple.com/content/attachment/f5434705-14a7-44c0-8b13-1e9bdb2cd43a
This continues today with Big Sur adding a Signed/Sealed System Volume— as well as Monterey.
I would just click to Eject All. This is not an issue.
This should only occur if macOS is installed on the external SSD. Otherwise, there should be no reason to have two volumes on the external SSD by default.
Hi Alfredo,
It doesn't look like your attachment got saved in your post. Can you please do the following to describe the volumes on the external SSD:
Just to add... I'm trying to figure out if this is a Big Sur thing or not. On my High Sierra MBP, erasing (formatting) an external SSD shows up as a single volume. If I try to eject it, it doesn't indicate more than one volume. When I did this on my son's new 2020 MBP, it shows up as 2 volumes.
I just realized something. I used this external to clone from the internal HD. Now I'm wondering if using Carbon Copy Cloner may have changed the formatting to accommodate the Big Sur internal HD...
Good to know! In that case, if you cloned an installation of macOS Catalina or later (Big Sur, Monterey), then yes - your clone should have two volumes visible in Disk Utility.
(In reality, there are 3-4 hidden volumes as well: Preboot, Recovery, VM, and maybe Update.)
This was happening on my son's mac and he is back at school. As soon as I can get him to answer my texts, I'll ask him to check. I'm re-attaching the screenshot.
Thanks for the link. That explains it. So I assume if I decide to upgrade my High Sierra to Big Sur, my drive will be updated to contain the read-only system volume. Good to know.
That makes sense. The screenshot was from inside of Carbon Copy Cloner after I cloned the internal HD.
Why does external disc have 2 volumes?
