partition map check failed because no slices were found I own an early 2011 MacBook Pro running Mac OS X Mavericks. Recently, I tried to make 50 GB partition using Disk Utility but the whole process didn't complete, and I had to restart the system as it hanged (Even Force Quit wasn't working). Upon reboot, I saw that I was missing 50GB space. When I tried to verify the disk, it showed me the following error:

"Partition map check failed because no slices were found."

Can I fix it without using external drive? Please help.
Reboot into Single User Mode (hold cmd-S on boot)

Run /sbin/fsck -fy
fsck is File System Consistency checK. -f forces the process, and -y assumes yes.
This will basically run Disk Utility's Repair Disk, but outside of the OS so that is has full read/write to the disk.

Once complete, reboot