Now the fix for the issue is a matter of clearing the problem with the filesystem structure. If this is the case, hold the power button to hard-reset the system, followed by holding the Command-Option-P-R keys at startup (immediately after the boot chimes) to have the system clear the PRAM so it will load normally instead of in Safe-Verbose mode (release these keys after the system automatically resets and sounds the boot chime again). This process should only take a couple of minutes, but if it does not progress after an extended period of time, then it is not able to check the disk for errors and is hung up, which is the cause for the inability to boot to Safe Mode. The system should at some point load a routine called "fsck_hfs," so look for it (this should happen relatively quickly, and then pause on this process for a few seconds while it checks the file system structure files mentioned above). With this command run, reboot the system and you will see it load into a text environment with the most recent events happening at the bottom and the history of events scrolling upward. With the disk device selected, the Partition tab will be available you can use it to repartition the disk and format it. In this command I've used "Safe-Verbose" mode, but you can replace the "v" with an "s" to tell it to use "Single User" mode instead (they should be equivalent for this purpose): To do so, open the Terminal utility and run the following command. Unfortunately it is a bit difficult to see if this is the case when the system is only displaying a gray progress bar however, you can force the system to show you what is going on by having it boot to both Safe and Verbose modes at the same time. One of these tasks is a filesystem check on file systems structure using the tool "fsck_hfs," but if a problem occurs that prevents the tool from checking then it may hang and result in the system only loading to the gray screen with the Apple and a progress bar below it. When the system boots to Safe Mode it will show a gray progress bar that indicates various maintenance tasks are being run at startup. When you run a file system check with Disk Utility, you will see them listed as the Catalog file, the Extents file, and Extended Attributes file, among others. The HFS+ format includes a several indexing databases that hold information on where files are on the disk, and various attributes about them. In addition to the timing of the key press, be sure to check your keyboard's battery level and replace the batteries if they are low.Ī final issue that may prevent booting to Safe Mode is if there are problems with the boot drive's file system structure. Instead, if you have a wireless keyboard be sure to press and hold the Shift key after the boot chimes sound. While many instructions suggest that you hold the Shift key at startup to get to Safe Mode, the system's Bluetooth controllers will only activate after the startup chimes sound, so if the key is held before this, the key press will not be recognized. FileVault can be disabled in the Security system preferences using the FileVault tab, but the firmware password must be disabled using the Firmware Password utility that is available in the Utilities menu in the OS X installer (You can get to this in OS X Lion and later by holding Command-R at startup).Ī second potential issue that prevents Safe Mode from working is if you have a wireless keyboard. To enter Safe Mode, you must first disable these options. If you have Apple's FileVault disk encryption technology enabled, or if you have a firmware password set on your system, then the computer will not boot to Safe Mode. Some security settings in OS X may contribute to the inability to boot to Safe Mode. FileVault in OS X 10.7 "Lion" or later will prevent booting to Safe Mode.
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