If you are concerned about your Mac starting to run slow or become unstable, you may have looked into regularly running maintenance routines to clear caches, log files, and other temporary items from your system.
You may have even seen advertisements for programs that automate these tasks.
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.
These options work like chkdsk on Windows, checking for disk and file system errors and repairing them.
You can perform a check from within Mac OS X, but it may sometimes be necessary to use recovery mode to fix problems.
While Disk Utility didn't notice any problems, at the end of its tests it said it was "updating boot support partitions for the volume as required." That sounded promising, and sure enough the install worked when I tried it again.If your computer does not shut down normally, they will be deleted during the next startup.Modern versions of Mac OS X no longer need you to repair disk permissions.While periodic maintenance of your Mac is usually not necessary to keep it running in top shape, one exception is periodically checking your hard drive for errors.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.