Missing volume after updating to High Sierra

[petisjioweelsha]

I've got an old MacBook (Mid 2010) with a physical HDD containing 3 volumes - each is a boot volume and all use FileVault2.
Under Sierra all of the volumes were visible in Disk Utility and in the Startup Disk System Preferences.

After updating from 10.12.6 to 10.13.6 one of the volumes is no longer visible in Disk Utility nor in the Startup Disk prefpane.
However, it does present a FileVault2 unlock prompt after login and it can be successfully mounted and read/written.
Holding 'Option' during boot also does display the volume in the Startup Manger and we can successfully boot into and use the volume.

I would really like to be able to mount this volume at will using Disk Utility instead of having to remember to unlock it at startup.

When mounted all of the volumes are reported aa Mac OS Extended (Journaled). It does not appear that any of them were automatically converted to APFS or anything like that, since this is not an SSD.

Is there anything I can do to make this volume fully recognizable or failing that - perhaps a workaround that will allow me to mount it al will?

 

[Brian33]

I don't know how to get it to show in Disk Utility, but if you're comfortable with Terminal commands I'm pretty sure you can unlock it when desired with the 'diskutil' command. Specifically, I think you'd use 'diskutil list' to identify the desired volume, and 'diskutil corestorage unlockVolume xxxxx' to unlock and mount it. You can display help for the diskutil command by entering 'man diskutil'.

Oh, just remembered that in Disk Utility there's a "Show all devices" menu item in the "View" menu -- give that a try.

 

[petisjioweelsha]

diskutil corestorage unlockVolume xxxxx' to unlock and mount it.

This worked!
I was able to unlock the volume in Terminal and then it became visible in Disk Utility for mounting.
This is great.
Thanks Brian33!

 

[Brian33]

Great! Glad to hear it!