Trying to shrink my default full disk partition to create some free space (for Ubuntu, incidentally, which I'm longing for even more now).
Partition failed Partition failed with the error: Couldn't modify partition map because file system verification failed
I've tried the advice here: http://osxdaily.com/2012/03/05/fix-partition-failed-error-mac/
Including booting to single user mode to run /sbin/fsck -fy and booting from the recovery partition to run disk utility to repair the disk and try partitioning there.
Verify disk seems to think everything's ok but I'm still at a loss as to how I can shrink the partition to create some free space.
Best Answer
Try booting from a USB drive and running Disk Utility from there on your drive, using this method in Disk Utility. You can just slide to resize the partition.