I created a second partition on my rMBP's SSD in order to install a bootable beta copy of El Capitan. I'd now like to delete this partition but am unable to. The minus button in Disk Utility is greyed out. A cursory search online suggests that this has something to do with the partition being turned into a Core Storage volume.
How do I go about deleting this partition?
Main partition running OS X 10.10.4
iMac, Mac OS X (10.0.x), 2009 27" iMac
Open Disk Utility, select the second volume in the sidebar. Click on the Erase tab in the main window and click on the Erase button. Please backup the first partition in case this fails.
Open Disk Utility, select the second volume in the sidebar. Click on the Erase tab in the main window and click on the Erase button. Please backup the first partition in case this fails.
I hope that before you started this you made a fully bootable copy of your original setup (pre second partition) because you are going to need it.
You will basically have to boot into the old Recovery Partition to access the old Disk Utility app. Wipe the drive and clone back or start again: clean install.
I'm guessing that when you currently try this, DU is either not responding with greyed out buttons or you are forced into El Cap's DU, which is a PITA and unfinished at present?
Once in the old DU in Recovery, you should now be able to wipe the entire drive/HD allowing you to either clone back your old system, or start a new with Yosemite.
What you experienced is exactly what happened to me. However, I was cautious enough (as I'm guessing you have been) to have prepared a safety net prior to delving into DP (not Beta; which incidentally is different) OS testing.
Best of luck and in a few hours you should be back up and running.
Click on the Erase tab in the main window and click on the Erase button.
I'm looking to remove the second partition altogether, not just erase its contents.
Have you tried my suggestion... Re: just getting into Yose's Rec Partition... That might enable you to remove the unwanted Partition?
Edit ADD INFO: And have you enabled / disabled FileVault 2... which can prevent you from messing with Partitions? It has to be turned off, which then reverts it back to standard storage and not a Logical volume.
It is a PITA but resolvable with a little work.
Why on earth should I have to wipe the entire drive?
Perhaps I didn't make myself clear. I did not install El Capitan on my main partition, which is running Yosemite. I created a second partition and installed El Capitan there with a dual boot setup so that I could safely test it. Both installations work just fine - I just want to delete the second one.
I have not attempted anything other than running Disk Utility from Yosemite, where the partition controls are greyed out.
I undertsand what you have done, and you have done exactly what I did.
However, because El Cap think's it is the Logical Volume, alongside Yosemite, which also thinks it is a Logical Volume, you have hit a brick wall.
If you go into either OSs' DU the option to resize, or delete the partition is greyed out? Correct? And if not, then you have found a way to resolve your issue without further delving.
However, if it is greyed in both OSs', the only way to resize/delete the parttion you do not need is to boot into the Rec Partition, preferably of Yosemite, which has the old DU app, performing the steps you need. However, if, even in Rec Partition the option to resize/delete is not available, then you will have to format and clone or start again.
I'm offering a number of options to test before you may have to destroy your setup in order to bring it back.
I booted into the Recovery partition but Disk Utility there still has partition controls greyed out. Is this BS a bug or is it by design? At no point was I warned when creating the partition that its removal would require wiping the drive.
Neither was I warned other than the massive DP listing on the filename before installing. It's an issue with El Cap's DU because the app is unfinshed and this is listed. It's also as a result of Logical Volumes and the like, which is even beyond my understanding. However, because of the NDAs surrounding El Cap, we shouldn't even be discussing it.
Sadly it's a nusiance to fix, but very fixable if you did take a back up. if you havent though, you still can.
My advice would be to download CCC (Carbon Copy Cloner) use the free trial and clone a bootable of your Yose OS. Then wipe and clone back your setup. And take heed of using DP/Beta software. As enticing as it is, it realy isn't worth it, half the time.
Good luck.
Oh and another tip for you. If and or when you ever clone back on OS on Apple Hardware. Once it's completely done and up and working, reset the PRAM, this will clear out the old and speed up the boot process.
I wish you well.
Well, I was unable to access the Recovery Partition by rebooting with the Option key. I then rebooted with Command + R, though, and this got me into OS X Recovery. However, Disk Utility still had all the partition resize and deletion controls disabled.
I read some comments questioning whether the second OS installation may have replaced or deleted Yosemite's recovery partition. A quick Terminal command seems to confirm this is not the case.
...It's an issue with El Cap's DU because the app is unfinshed and this is listed. It's also as a result of Logical Volumes and the like, which is even beyond my understanding...
...download CCC (Carbon Copy Cloner) use the free trial and clone a bootable of your Yose OS. Then wipe and clone back your setup
I'm always cautious with DP/beta software, but it was always my impression that installing in a separate partition was a relatively safe bet. Lesson learned. Of course, that's assuming this is El Cap's fault, and that Yosemite doesn't share the blame. After all, my search for answers revealed eerily similar questions and complaints from last year when Yosemite was the new kid on the block.
In an older Macrumors thread, some folks reported partial or complete success using a couple of different approaches:
http://forums.macrumors.com/threads/help-cant-delete-yosemite-partition.1755242/
Solution 1:
Solution 2:
Try erasing the second partition using Disk Utility and then delete it. (Also suggested in this thread by Kappy)
The first solution doesn't seem appealing, given one user's outcome.
The second solution sounds tempting but at this point I'm afraid of making things worse.
Worst case, I suppose it's not the end of the world since my data is backed up and I'll probably want to wipe the SSD anyway for some upcoming warranty work. https://www.apple.com/support/macbookpro-videoissues/
I thought exactly like you, re; Second partition installations and the like. And I suffered the above, just like you. From what I read at the time, it's all about the Logical Grouping of the installations, and it may well be that both Yose & El Cap are to blame.
However, I had a literally moments before meddling with El Cap, CCC'd my Yose system. So, I managed, as per my advice above, to completely wipe and clone back the CCC. It took a few hours, a little head scratching, a lot of key command boots, but I managed it.
Thanks for the detailed response above. It's a shame that this has happened. But as long as your data is safe, that's most important.
Best of luck.
I may have missed something, so excuse any repetition. I suggest:
1. Remove any encryption on the 10.11 partition from Preferences>Security. Give time to complete the task.
2. To see the full picture in Yosemite DU, invoke Debug mode and then "View all Partitions"
defaults write com.apple.DiskUtility DUDebugMenuEnabled 1
3. Remove the Core Storage
First use
diskutil cs list
To revert - diskutil list
Then look for the disk identifier of the logical volume itself (not the physical), which should be "disk1" or "disk2"
Then do
diskutil cd revert “yourdiskname'
Im my case, that was:
diskutil cs revert disk1
4. A simple removal of the second partition should remove the 10.11 OS, without any need to Erase first.
5. Boot into the 10.10 RP and run the DU Repair disk, from outside the system.
I'm thinking the greyed out partition is because of the encryption, but may be more complicated with Rootless attributes in 10.11. The 10.11 DU is still in it's infancy.....
I really appreciate the tip, but I'd rather not decrypt the drive. This is an SSD, which is impossible to securely wipe. So for my peace of mind when I resell it some day, I do not use it unencrypted.
If you can boot from an external disk with 10.10 on it, maybe it's DU would be more successful. Did you enable the Debug menu to see the RP's?
I finally got rid of the partition, through a combination of suggestions from Kappy and Putnik. The trick was to boot from an external drive (in this case an install drive I created on a USB thumb drive), run Disk Utility, and erase the second partition from there. For some reason I was then unable to actually delete the partition from there. But when I rebooted into Yosemite, I was finally able to delete the partition with Disk Utility.
it was not necessary to disable FileVault in either partition.
Thanks for your help, all.
Can't delete second partition
