Problem creating new image after YoYo upgrade due to Disk Utility issue

[david_yenzer]

Good morning all,
So my normal image creation process is pretty simple...I update a machine to how I want it, then boot to an external drive, open disk utility, click on the drive, then click on "New Image" and save a copy (upload to Casper, blah blah blah).

I'm not sure on the appropriate terminology, but normally in Disk Utility when I click on the drive it says something like "500.11 GB Toshiba MK..." and then Disk Utility gives me the options of: First Aid, Erase, Partition, RAID, and Restore. Then if you click on the sub-disk area labeled "Macintosh HD" you get the options of: First Aid, Erase, RAID, and Restore.

NOW all I get in Disk Utility is two items labeled "Macintosh HD" and no option to create a "New Image" and save a copy.

Is there a way to fix this either in Disk Utility or via upgrade process? I've tried reverting to Mavs and upgrading to YoYo (1) via Self Service; (2) via copied YoYo.app; and (3) redownloading the entire YoYo.app from the App Store. They all result in the same thing...something I can't copy. I have not yet tried a different drive - but note that I was able to get a master copy on our MacbookPros, I am having trouble with the Air image (and don't have a SSD to swap out for testing). However, it does appear that a few of the Pros also have experienced this issue - I just don't know if I care since I at least got a master image that I could then reimage them with if needed.

Thanks in advance!

[david_yenzer]

I will test on another mac air, see if that makes a difference.

[wubbelsl · Accepted solution]

Yosemite likes to switch regular partitions to Core Storage volumes on some devices - usually with SSDs. You can revert it using terminal:

diskutil cs revert /dev/disk0s2

Change disk0s2 to whichever partition has OS X Yosemite on it.

[david_yenzer]

Score! I had to do a quick "diskutil list" command in Terminal to find that my command was actually

diskutil cs revert /dev/disk1

but after a reboot all looks to be back to normal and I've got my New Image command back to make a copy. I finished the process and everything plays nice now.

Thanks!