… for Random Weirdness
Tip #098: What’s the Best Way to Repair the Boot Disk?
Not all repairs work the same – this is better.
A common question, when it comes time to maintain your computer system, is whether it really makes a difference to switch to Recovery mode to repair a hard disk. There are two answers:
- No, if it is an external disk
- Yes, if it’s the boot disk
While we can repair an external drive at any time, we really can’t repair the boot disk when it is running AS the boot disk. By definition, all the OS files need to be open and active and we can’t repair an open, running file. Disk Utility compensates for this, but it can’t do a complete repair.
By launching into Recovery mode, we are booting from a completely different part of the hard drive, using totally different files. This allows Disk Utility to fully repair everything on the main boot disk – Macintosh HD – without interference.
To launch into Recovery Mode, restart your Mac while pressing Cmd + R. Startup will take longer, but, when complete, you’ll be able to run First Aid from Disk Utility. I try to do this once a month or so.