Can't resize disk partitions after Yosemite install.

My disk has two partitions. I run Mavericks on the first, and recently installed Yosemite on the second. The OS works fine, but I no way to resize the partitions. I've tried booting into both Yosemite and Mavericks but the partition layout in disk utility appears locked with fixed partition sizes.


It now appears that I have two options.

  1. Use the undocumented "resizeVolume" command in diskutil to resize the core storage volume in my Yosemite partition, or
  2. Use the "revert" command in diskutil to revert from core storage to the default partition type and try my luck.


Is anyone else facing this issue of not being able to resize your disk partitions after the Yosemite install, and if so, how did you resolve this?

Thanks in advance.

MacBook Pro, OS X Yosemite (10.10)

Posted on Oct 17, 2014 8:35 AM

Reply
4 replies

Oct 19, 2014 3:42 AM in response to rssg

None of these worked. I had to resolve this the hard way.


  1. Make a complete TM backup of the new Yosemite installation.
  2. Use a bootable install DVD or USB drive, re-partition the disk and do a complete reinstall.
  3. Recover the applications and data from the TM backup.

It took me about an hour and a half once I decided on this approach, not counting the hours wasted trying to get it working.


To give them credit, the TM backup and restore worked flawlessly and all my apps and data were back without a hitch.


However, reading the other posts in the forum and elsewhere it does appear that Apple has not done a good job with the disk utility in supporting core storage volumes, which is fairly ridiculous since Yosemite defaults to that without giving you a choice.

Nov 2, 2014 3:08 AM in response to rssg

Same here. I got 2 partitions. The first one is running Yosemite. The second one was for testing, now its just "Free Storage" of 30GB. I am not able to resize both of them. Would like to merge the Free storage of the second one on the first partition. Looks like there is no possibility doing that by using Yosemite....(also tried doing this in recovery Mode)

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Can't resize disk partitions after Yosemite install.

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