What happened: I upgraded to the Yosemite public beta, which messed up my boot record (?) and rendered my bootcamp partition unbootable. In the process of trying to save my Win 8.1 partition i ended up with a completely empty partition table. The current situation: i can boot my mac into internet recovery but diskutil shows only one partition on my 500gb harddrive. the previous partitions were: 1: mac partition - filevault, yosemite public beta (SHOULD BE RECOVERED): was ~320 GB in size and the standard mac partition at the beginning, which got shrinked at the end to fit the bootcamp win partition (2). the mac partition uses filevault and runs as mentioned the yosemite public beta. 2: windows 8.1 bootcamp partition (CAN BE DELETED) the question: can i somehow recreate my partition table and make my mac partition bootable again? if the windows partition is lost, so be it, as long the mac one is saved. TestDisk looks promising as i assume i have to somehow scan my harddrive for partitions and recreate the partition table manually. How should i continue? if you need any additional information just ask! thanks in advance for any help!