diskutil repairDisk disk4
Repairing the partition map might erase disk4s1, proceed? (y/N) y
Started partition map repair on disk4
Checking prerequisites
Checking the partition list
Adjusting partition map to fit whole disk as required
Checking for an EFI system partition
Checking the EFI system partition's size
Checking the EFI system partition's file system
Repairing the EFI system partition's file system
Updating boot support partitions for the volume as required
Creating a new EFI system partition
Checking the EFI system partition's folder content
Checking all HFS data partition loader spaces
Checking booter partitions
Checking booter partition disk4s3
Verifying file system
Checking Journaled HFS Plus volume
Checking extents overflow file
Checking catalog file
Checking multi-linked files
Checking catalog hierarchy
Checking extended attributes file
Checking volume bitmap
Checking volume information
The volume Boot OS X appears to be OK
File system check exit code is 0
Reviewing boot support loaders
Checking Core Storage Physical Volume partitions
Updating Windows boot.ini files as required
The partition map has been repaired
Finished partition map repair on disk4