Tag Archives: High Sierra

MacOS – Creating a clean initial image

To create a “clean” image –

Basic goal – you don’t want anything except the basic MacOS installed. So be certain that the mac serial number is not scoped to a JAMF pre-stage enrollment. You don’t want JAMF to install or anything else to install.

Take a mac out of shrink wrap (or use internet recovery (cmd-opt-R) to erase the internal hard drive and re-install a Mac OS).

Let the MacOS setup run and disable (or not enable) everything you can. Create an admin account that you want to use for all computers this will go on.

Run system updates and update all MacOS software.

If they are not installed, install iMovie, Pages, Keynote, Numbers, and GarageBand. Run GarageBand to make sure the required Apple Loops are downloaded and indexed.

In a terminal window switch to root (sudo -s) and give the following commands:

  • systemsetup -setcomputersleep 120
  • systemsetup -setdisplaysleep 120
  • systemsetup -setremotelogin on
  • softwareupdate –schedule off

These commands are useful when remotely connecting to the mac after imaging.

Once done, shutdown (not reboot) the mac. Then boot to an external disk that is loaded with the same or greater version of the MacOS and run an up-to-date cloning application like Carbon Copy Cloner. Take a read-only, compressed image of the internal hard drive “Macintosh HD”. Copy this into your image distribution system.

Since MacOS 10.13 – High Sierra – You must use an image taken from an APFS formatted drive to “image” other APSF drives. Likewise, use an image taken from an HFS drive for HFS drive imaging.

Also, you can not simply image an MacOS 10.12 or lower with a MacOS 10.13 image. The MacOS 10.12 mac must fist run the native MacOS 10.13 installer from Apple. That installer both installs firmware required for booting a 10.13 system and formats the drive as APFS or not depending on drive type. All SSDs are formatted to APFS without option. As of 10.13.5, Fusion drives and HDD drives are left as HFS.

Mac – Reset SMC for slowness or wake/sleep issues

The SMC (System Management Controller) controls a number of things related to power management on a mac. If it isn’t working properly it can cause fans to run, the cpu to run slow, and/or, the mac not to wake from sleep when it is supposed to.

On most mac desktop (not the new imac pro), you reset the SMC by:

  1. shut down the computer
  2. unplug the power cord
  3. wait at least 15 minutes
  4. plug the power cord back in wait 5 seconds more
  5. turn the computer on

More Details:
https://support.apple.com/en-us/HT201295

Mac – Tool to help download specific macos installers

It isn’t always easy to get all of the right pieces for a particular MacOS update/install.  For example, if you are running MacOS 10.13.5 already the traditional ways of going to the Map App Store or doing system updates won’t offer you MacOS 10.13.4.

Thanks to dedicated mac folks on the interwebs we now have a tool. See:

https://derflounder.wordpress.com/2018/02/27/using-installinstallmacos-py-to-download-macos-high-sierra-installers/

and

https://github.com/munki/macadmin-scripts/blob/master/installinstallmacos.py

Mac High Sierra – Imaging APFS formatted disks

Back when High Sierra (MacOS 10.13) was coming out we were all told that disk imaging would be dead because of the new APFS disk format.  And, while It is true that you can not/should not apply a High Sierra disk image to a Mac running an older OS and hope for that to boot correctly, apparently you can “image” a High Sierra disk and apply it to another Mac that has already been upgraded to High Sierra.

First things first – 

To upgrade a Mac to High Sierra you have to run the “Install High Sierra” update.  This is available from the App Store which places a copy of the install app in the Applications folder.  You can copy that to however many Macs you need to update. That update not only upgrades the OS but it also applies firmware that High Sierra needs to boot properly and, if the Mac has an SSD, if converts the disk format to APFS.

You will need to do this upgrade on all the Macs you will use in this process.  In other words, to take an image of an APFS High Sierra Mac you must be booted to an external drive or some other system that is also a High Sierra APFS formatted drive.

Next prepare your image –

Using a Mac that has already been updated to High Sierra, do an internet recovery (hold command-R at boot) to first erase the hard drive and then reinstall the MacOS.  This gives you a completely clean copy of High Sierra.  You will then want to configure that as minimally as possible. Once configured, boot to an external drive with an up-to-date version of High Sierra installed and run Disk Utility.

In Disk Utility, click on View to “Show all Devices”. Then right-click on “container disk1” and select “Image …” ..

Once the image is created, transfer that to your JAMF server (or other image deployment server) and let it rip ….

A couple of final notes:

  • If you are like me and will have both APFS formatted and HFS+ (non-ssd) drives, you will need to take a similar image in the same way from a Mac with the legacy HFS+ drive format as well.  Apply the APFS image to APFS-only drives and HFS+ to your HFS+ drives.

 

 

Mac OS – High Sierra – Run installer from command

The High Sierra installer not only installs the new OS but it also changes the disk format form HFS to APFS on SSD drives.  Additionally, it does the required firmware updates for the model of mac that the installer is being run on. Therefore, it may be necessary/easiest to run this installer on each mac before applying a High Sierra image to the mac.  The command to do that is:

/Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall --applicationpath /Applications/Install\ macOS\ High\ Sierra.app --agreetolicense --nointeraction

(obviously you have the “install macOS High Sierra.app” in the /Applications folder for this to work)