If you're using Google Chrome as your browser, look at the top right corner, at the end of the search bar. Near the bottom of the list, there is an option that says "Empty cache." Select it.
Both of these can be used to check the hard drive for errors, using the following syntax: diskutil verify Disk DRIVEID diskutil verify Volume VOLUME In these commands, DRIVEID is the device ID of your boot disk, which usually is "disk0," but may be another value such as "disk1" or another number if you have multiple physical drives in your system.
You can look this up by running the command "diskutil list" to show the available devices and their respective device IDs.
Therefore, be sure to run "disktuil list" again before running the command to find out the proper ID to use.
Apple has offered a Safe Boot (sometimes called Safe Mode) option ever since Jaguar (OS X 10.2.x).
This is especially true if you use an outdated version of these software packages that may have a bug or two in it.
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.
Do note that checking the hard drive will pause writing to it, and since the system is continuously writing and updating data on the drive, this may result in the system hanging for a few seconds while the checking routines run, so do not be alarmed if you see the spinning color wheel cursor and cannot perform other tasks while this routine is going on.
However, even if the system seems paused for a long time, the routine should resume sooner or later.
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.