Fast way to reinstall/image only the OS?

New Contributor III

I am looking at the fastest way to reinstall macOS with a service that is easy to update the version of the OS as new version come out. Netbooting would be a great option but not necessary.

Thanks in advance for the help :)


Contributor III

I prefer netboot at this time, as we have a lot of field techs (not Mac savvy) who reinstall MacOS and its easier to just maintain the NetInstall version on various sites across the company, then to have them make multiple USB drives. SO thats my recommendation at least.
We just have not found a particularly clean and easy way to replicate it automatically. ie; we update NetInstall macmini1 > then have to manually update NetInstall mini2, etc

New Contributor II

Question on side lines : we need to keep a mixed environment and different users need seperate roll outs of different os versions?

Valued Contributor III

Prior to yesterday, I would have encouraged migrating to a vanilla Apple System Image Utility-generated NetInstall as it's Apple-supported technology to deploy just the operating system.

Unfortunately the world learned yesterday from Apple that the iMac Pro will no longer support starting up from network volumes in any form. (

While the Apple IT world has been talking about the demise of imaging, this may well lead us closer to that. I am betting new Macs going forward will likely have the same secure boot technology. I'm hoping Apple gives us some kind of tool to revert the OS back to a clean state. Internet Recovery is okay I guess given my new work flows but it isn't terribly automated and re-provisioning large groups of lab Macs kinda requires just a bit of automation.

Luckily I am already starting the process of dumping traditional imaging and have made great strides using scripts, packages, policies and profiles but the one missing link in the whole thing is what @warrenmc originally posted does one get a computer reverted to a shiny clean operating system so they can hand a device over to new users or refresh lab software using Apple-supported tools? For this I can only hope that Apple will supply an answer sooner rather than later that doesn't require hand-initiated Internet Recovery.

New Contributor III

@blackholemac thanks for the information.

I had our engineer set up Deploystudio before, but am looking for a different tool since I kept having issues with it. It was able to erase the whole partition map, reinstall, and set the time to work with our servers all in about 3-5 minutes. It was amazing.

I might just try to fix that server now. Around the holidays it's tough to keep up on that stuff though since everyone is out of the office.

Valued Contributor III

What I've looked into is using Casper Imaging on a USB drive to perform a scripted restore of the OS using assets from the local distribution point. The technician is going to have to perform some sort of alternative boot method to reinstall the OS, and this would be way faster than Apple's "reinstall the OS from the installer" method.

I like the idea of Netinstall, but supporting it at dozens of sites with locked-down networks is too much to manage.

Our imaging method has been modular for many years, but getting that bare OS laid down is the biggest challenge now. It's not difficult to do, but it's time-consuming and requires a lot more interaction than it used to. I need to make the output easy, fast, and consistent before we start installing packages and running scripts.

New Contributor III

For my purposes, it will be just ONE lab network that needs some type of server. Do you guys think that it would be good to use Casper Imaging?

New Contributor III

Just thought I would update everyone on this post.

All I needed was a netboot to reinstall the base OS. I'm going to stick with DeployStudio. I'm testing to see if it works with 10.13, but as of right now all our machines are on 10.12.6. The OS reinstall usually takes 3-5 I think that is the quickest I am going to get :)


This is sweet. Reinstall a clean macOS with one button -

New Contributor III

Thanks so much @prl! That's great!