Disk utility updating boot support partitions volume required
To create your own bootable disk, refer to our blog ‘Creating a Mavericks bootable install disk’.
I would strongly recommend at this stage attempting to back up any data that is required before proceeding with the following steps.
If your Mac's hard drive is experiencing formatting errors, then the system may show slowdowns, failures to properly save or read data, and even file corruption, and eventually it may not even boot.
To use the fsck command, you can run it with the following flags to perform the repair: sudo fsck_hfs -fy /dev/disk0s2 Keep in mind that when booted to the OS X installation or recovery drive, the "disk0" ID will likely now represent the recovery drive instead of the system's main boot drive.
Since OS X systems generally have an EFI boot partition, this usually offsets the boot drive's slice number to be disk0s2.