A Safe Boot performs the following permanent actions: attempting to repair the system volume structure, deleting system KEXT caches, and deleting font caches.

The master password is used to reset local account passwords.

Each user starts with a login keychain saved at /Users//Library/Keychain/ login.keychain and a Local

Items/iCloud keychain saved in the /Users//Library/Keychains/ folder. Administrative users can manage systemwide authentication assets with the /Library/Keychain/System.keychain. Finally, Apple maintains several items in /System/Library/Keychains/ for OS X system use.

Spotlight metadata index databases are stored at the root of every volume in a /.Spotlight-V100 folder. However, a Legacy FileVault user's database is stored in his encrypted home folder. And the Mail application maintains its own database in each user's home folder at ~/Library/Mail/V2/MailData/Envelope Index. Spotlight plug-ins can be located in any of the Library folders in a folder named Spotlight.