Repair Disk Permissions after OS X upgrade

I have recently upgraded to the free OS X Mavericks and after the upgrade for both my MacBook Air 2012 and Mac mini late 2009, both machines experienced slowness in starting up and shutting down. In addition, the screen sharing functionality is extremely slow.

I managed to resolve this issue by doing a repair via the Disk Utility. To repair your Mac, just do the following:

1. Use Spotlight and search for Disk Utility
2. After running Disk Utility, select Macintosh HD, which is usually the main harddisk that stores your operating system files
3. Click on Verify Disk Permissions. If prompted for a login, key in the administrator user ID and password.
4. Click on Repair Disk Permissions after verification of the disk permissions are completed. If prompted for a login, key in the administrator user ID and password.

Once completed, restart the mac and the speed and the screen sharing issues should have been resolved. It worked for me.