Updating boot partitions for the volume as required
There are also alternatives to the Disk Utility program built in to OS X.
These can be used either if you are logged in in Single User mode (after holding Command-S at startup to drop you to a root terminal prompt instead of loading the OS X interface), or if you are logged in remotely through an SSH connection.
Disk Utility responds by stating what it’s about to do: Click the blue Run button to begin the process of verifying the disk.However, there are several alternative, manual ways to check for and fix hard-drive errors. This is the standard and recommended method for checking the system's hard drive, since the graphical interface is quick and intuitive to use.Simply select your boot volume in the device list (this will be the name of your boot drive), and then hold the Option, Command, or Shift key and select the drive device itself, which will have the size and manufacturer in its name.The third option is to simply target the root of the boot filesystem using a single forward-slash character.The following are examples of all three of these options: diskutil verify Volume "Macintosh HD" diskutil verify Volume Macintosh\ HD diskutil verify Volume disk0s2 diskutil verify Volume / When you run these commands, the system will check the boot drive and output status similarly to what is seen in the Disk Utility log window.