Last night I was going to partition my HDD (to try out Yosemite). I started Disk Utility and proceeded to allocate space to my new partition and clicked start. After a while, my MacBook had a sudden shutdown (charger was not connected). I booted it up only to discover that there was no new partition, yet the space I allocated to the new partition is still being used! Does anybody have an idea about what to do? 34,68 GB are now 'lost'.