When i tring to start my mac, the operating system cannot be opened, even if i restarting or shuting it down and start it again.
Just the background only appeared.
How can i repair or fix the OS
The 2nd question, i have to take a backup in time machine by a storage capacity equal or more than the data size in my mac, or can i use a storage less than the current data by selecting specified data plus the os to take a backup
Mac Pro, OS X Mountain Lion (10.8.2), Os not opened
Mac OS X: Gray screen appears during startup
The above is outdated but the troubleshooting steps remain applicable. Try restarting using OS X Recovery.
Time Machine requires sufficient space to create a complete backup of your entire source volume's contents. It will require more than that to be useful, but does not necessarily have to be equal or greater than the source volume's size.
To exclude items from Time Machine backups, use Time Machine Preferences and select the Options button.
Mac OS X: Gray screen appears during startup
The above is outdated but the troubleshooting steps remain applicable. Try restarting using OS X Recovery.
Time Machine requires sufficient space to create a complete backup of your entire source volume's contents. It will require more than that to be useful, but does not necessarily have to be equal or greater than the source volume's size.
To exclude items from Time Machine backups, use Time Machine Preferences and select the Options button.
OS Not opened
