macOS Sierra SmartCard Commands

Here are a few useful commands for working with SmartCard pairing in macOS Sierra and later.

This command will show the hash of the user name you specify.
sc_auth list username
You can then use that hash to unpair card if you need to using the following command.
sc_auth unpair -h hash (hash is the hash string that is produced from the sc_auth list username command.)
To enable or disable native smartcard pairing all together run use the following commands.
sc_auth pairing_ui -s disable
sc_auth pairing_ui -s enable

For more information regarding the sc_auth commands you can check out the Man pages for sc_auth.

macOS High Sierra 10.13.2 supplemental update fails to install

We haven’t quite updated our fleet of Macs to macOS High Sierra for a variety of reasons. Some of our users have admin rights and performed the update themselves. We have purchased a number of new MacBook Pro’s that came pre-installed with macOS High Sierra to replace the Macs that are no longer upgradeable.

In the last few days I have had to help a couple of my High Sierra users with an issue they had with installing the OS X 10.13.2 supplemental update. They perform the update and when the computer reboots a message pops up saying “macOS cannot be installed on your computer”. The only option is to restart computer. When the user restarts the computer, they get the same error message and end up in a reboot loop.


For whatever reason it seems the installer is damaged and won’t install. Thankfully, it’s a pretty easy fix. You can boot into recovery mode holding CMD + R while computer is restarting. Go to the Apple Menu and Select Startup Disk. Select Macintosh HD (or whatever your HD name is) and reboot. This will reboot your computer and allow you to log in as normal. Go to the App store and install the supplemental update. It should install successfully this time.

Keeping up with the Mac Admins

It’s been a while since I’ve been able to sit down for a moment and write. There are many posts I’d like to write, or, at least get started on, but I have not had the time. I am currently studying for my Linux + certification. Studying has consumed my already limited time.

I wanted to take a break from studying and write a quick posts for those who may have just started as a Mac Admin. I don’t claim to be a Mac Guru, but along the way I have found some valuable resources, which have taught me a lot about Mac administration. I thought I’d share these invaluable resources with you.

Believe it or not Twitter is a wealth of knowledge for Mac Administrators. If you don’t have a Twitter account, I suggest you sign up. If you search #macadmins you can find a lot of current information on what’s happening in the Mac community. You will also figure out who you should follow on Twitter for the current events in Mac administration.

Next. If you’ve never heard of Slack or  don’t know about the Mac Admins slack channel, you need to sign up right away. There are over 12 thousand Mac Admins on the Mac Admins slack channel. You can join channels such as HighSierra, Munki, MicrosoftOffice, etc. The list goes on and on. To sign up for slack go to and create an account. You won’t be sorry. Become an active participant. You will learn so much, and contribute your knowledge.

Finally, I highly recommend the MacAdmins podcast hosted by Tom Bridge. New episodes are published every Monday. The podcast is entertaining and informative. The information I have learned from this podcast, I have been able to share with my organization to solve real world problems. Just go there. Listen. You won’t regret it.  Search for MacAdmins in your podcast player or go to for the shows and show notes.

Anyway, back to studying…