Best Practices before doing any Mac OS System Upgrade

  1.  Read the info on compatibility with your software:
    OS X: About incompatible software – https://support.apple.com/kb/HT3258?viewlocale=en_US
  2.  Always back up your data.
    1. Make a good and complete backup with Time Machine and/or make a copy of your disk with Disk Utility.
    2. How to back up and restore your files – http://support.apple.com/kb/HT1553
      Time Machine 101 – https://support.apple.com/en-us/HT201250
  3. Understand how to restore your backup (you did make that backup!) before you start.
  4. How to back up and restore your files – http://support.apple.com/kb/HT1553
  5. Make sure that all software updates have been completed before upgrading.
  6. Repair the startup disk with Disk Utility before upgrading and after upgrading.
  7. Download the latest OS X install application from the App Store or from Software Licensing and install.

How can I get MacOS X on site license?

There is no free site license for MacOS X at NC State.

Departments and Units

  • Departments and Units can order licenses at a greatly reduced cost from the NC State Apple Volume License Agreement (VLA).
  • Contact Software Licensing about the Volume License Agreement.

Personal Computers

To get macOS for an individual home computer, download it from the OS X App Store application available in OS X 10.6.8 and newer.

Where can I find resources to help me with the Macintosh?

A list of resources that can be used to help solve Mac OS X issues.

www.apple.com/macosx – Mac OS X overview
www.ncsu.edu/mac- OIT Mac Page
www.versiontracker.com – Updates
www.macupdate.com – Updates
www.macosxhints.com – Support
www.apple.com/support – Support
docs.info.apple.com/article.html?artnum=2238 – reset pmu, nvram, pram
www.alsoft.com/DiskWarrior/ – Disk Repair
www.micromat.com – Repair and Diagnostic
/System/Library/CoreServices/Software Update.app – Update Apple Software
/Applications/Utilities/Disk Utility.app – Imaging, Disk Repair, Permissions
/Applications/Utilities/System Profiler.app – Diagnostics
/Applications/Utilities/Console.app – Logs
Terminal commands ls, chown, chmod, etc, – File permissions
Other BSD command line tools like fsck in single user mode

How can I securely format my Macintosh Hard Disk?

Apple Tech Note 107437 gives this procedure:
Steps for zeroing data

These steps assume you have a CD for Mac OS X 10.2.3 or later.

  1. Insert the Mac OS X CD.
  2. Restart the computer.
  3. Immediately after the startup sound, press and hold the “C” key to start up from CD.
  4. When the Installer screen appears, do not click Continue. Instead, choose Installer > Open Disk Utilities.
  5. Select the hard drive to erase.
  6. Click the Erase tab.
  7. Select the volume format from the Volume Format pop-up menu.
  8. Click Options.
  9. Select the checkbox for “Zero all data”.
  10. Click OK.
  11. Click Erase.

Also for those wanting to “Clean” individual files note this section from the technote:
“Secure Empty Trash.

Note: When you securely empty the Trash, the deleted data cannot be recovered by disk utilities. You should only do this if you have a backup or you are sure you will never need the data again.”

However, for those who want to take the time to be absolutely clean….

The relevant US DoD 5220.22M standard as best I can tell is at:

Under “8-306. Maintenance” which I think is the relevant section here.
Someone correct me if I am wrong.

NOTE: I edited this info to limit to relevant media. Read the web page for full info.

It states in brief:
Clearing and Sanitization Matrix

Media Clear Sanitize
Bernoullis a, b, or c m

Floppies a, b, or c m

Non-Removable Rigid Disk c a, b, d, or m

Removable Rigid Disk a, b, or c a, b, d, or m

a. Degauss with a Type I degausser

b. Degauss with a Type II degausser.

c. Overwrite all addressable locations with a single character.

d. Overwrite all addressable locations with a character, its complement, then a random character and verify. THIS METHOD IS NOT APPROVED FOR SANITIZING MEDIA THAT CONTAINS TOP SECRET INFORMATION.

m. Destroy – Disintegrate, incinerate, pulverize, shred, or melt.

So Non-Removable Rigid Disk (this was last updated in 1995) includes what we call today an internal or external hard drive.

Several programs that ship with macOS meet requirements for both Clearing and Sanitization.

  1. There is a format option in the Disk Utility application(on the install CD and in /Applications/Utilities) that does 8 Way Random Write Format of the disk which addresses matrix method d above. This could take several hours on a 250 gig drive.
    See Apple support article: http://docs.info.apple.com/article.html?artnum=152060
  2. This can also be done from the command line with
    /usr/bin/srm -rfmz /*.*
    and on a per file basis as well. If you are booted from another device like a CD, firewire hard disk, etc.
    From the man page of srm:
    -s, –simple
    only overwrite with a single pass of random data
    -m, –medium
    overwrite the file with 7 US DoD compliant passes
    (0xF6,0x00,0xFF, random, 0x00, 0xFF, random)
    -z, –zero
    after overwriting, zero blocks used by file
    So -s would meet clear, -m meets Sanitize, and -z is icing on the cake.
    No need to spend money on any kind or 3rd party software.
  3. Now what I suspect is that folks are going to want not only a method but some kind of boot cd or the like which will “make it go away”.
    I can imagine some ways using ISO CD images and some of the “free unix” distributions that one could make a hybrid, cross-platform, cross-hardware boot CD that would format all the disks in a machine. I do not have anything like that prepared at this time, and I am not sure we should be providing such a dangerous tool.