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Multiple macOS installer drives on one USB stick – GPT partitions, or Core Storage volumes?

FlyingToasterStrudel

FlyingToasterStrudel

macrumors newbie
Original poster
Oct 26, 2021
22
24
Hello.

I’m very adept at using the createinstallmedia command-line tool to make bootable installer drives on USB thumb drives. I’m about to embark on a project that will require me to update macOS on a bunch of somewhat older Intel Macs (approx. 2010 to 2020 era). For the sake of making more efficient use of the USB thumb drives I have on-hand, I want to take just one of my 64 GB drives and place five macOS installer drive volumes on it…
  • High Sierra (8 GB)
  • Mojave (8 GB)
  • Catalina (16 GB)
  • Big Sur (16 GB)
  • Monterey (16 GB)
(Possibly will be Mojave-thru-Ventura instead…)

I want to make sure this drive is readable and bootable on as wide a variety of Macs as possible.

My approach is going to be: to use Disk Utility to simply make five GPT partitions, with approximately the above-listed sizes.

But: I wanted to check with the forum first, to see if there is any advantage at all to using a different approach, eg. Core Storage logical volume groups or something? Is that even possible? Would I gain more flexibility down the road with such a strategy? Thanks.
 
GPT partition scheme with HFS+ partitions is the way to go.

You can try making one partition at a time. Use createinstallmedia. Then create the next partitition by splitting the one you just created, shrinking the old partition to the smallest possible size so that the new partition is as large as possible. Repeat until all the installers have been created.

Catalina might fit with 9 GB.
Big Sur, Monterey, and Ventura might fit with 14 GB.
Sonoma might fit with 15 GB.

If Disk Utility.app doesn't let you shrink the partitions, then use iPartition.app instead.
https://coriolis-systems.com
 
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I have made dozens of installer drives, and have been making multiple installer drives since Lion appeared.
I have a few with everything from Leopard to Sonoma on one drive. (It's a hobby...:cool: )
All use standard GPT with HFS+ partitions.
I think this will be changing soon, as there is a limit on one device of 16 HFS partitions.
but, I have recently been making what I call "modern macOS": High Sierra to Sonoma
Those are the ones that are most useful now.

I used to carefully craft the size of each individual installer partition, so there was only about 60MB of free space on each volume. I can get all installers from Leopard to Mojave, 10 partitions bootable, on one 64GB flash drive.
Can't do that with the "modern" systems -- but, then I also do this on NVME drives, with a 500GB often less than $40, no need for best quality/speed for this use, and much faster file transfer speeds (compared to thumb drives)
 
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startergo said:
Dayo automated this
Click to expand...
That script is actually for creating a bootable uni-installer disk each time. Something like the instructions by @joevt is needed to create a bootable multi-installer disk but AFAIK, createinstallmedia can't be used for the older Mac OS.
 
For some macOS versions it is not as easy as just restore it to a partition. There is this issue with the expired certificate. The common error message is that the installer disk is invalid. Setting back the date to 2016 does not work on every installer. Some files manipulations are required.
 
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joevt said:
createinstallmedia exists since Mac OS X 10.9 Mavericks.
Click to expand...
I see. Apple seemed to *imply* it was El Capitan here https://support.apple.com/101578 although I note they did not actually state so. I expect it was introduced with the "*.app" installers which I know Yosemite has and possibly Mavericks.

One negative about simply running createinstallmedia is that the resulting bootable disk can only be used on units that support that Mac OS version. So, you cannot create a Catalina installer with createinstallmedia and run this on cMP.

The Install_USB_Maker script reconstitutes the installers after stripping the supported unit and other requirements such as certs out before creating the bootable disk (Legacy *.dmg Installers ... Lion to LoSierra) or dumping the ISO for burning (Modern *.app Installers ... Yosemite to Monterey). Such can then be used for installation via OpenCore for instance.

Will get round to extending the script coverage to Sonoma. Also, using dd for bootable disk creation was painful for the modern installers. So I decided to ditch this and ask users to use Etcher themselves. Will look at dealing with that later.
 
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Dayo said:
I see. Apple seemed to *imply* it was El Capitan here https://support.apple.com/101578 although I note they did not actually state so. I expect it was introduced with the "*.app" installers which I know Yosemite has and possibly Mavericks.
Click to expand...
I have a Install OS X Mavericks.app
I searched all the installers for the createinstallmedia command:
Code: 
cd "/Volumes/Updates/System Software"
find . -name 'createinstallmedia' -path '*/Mac OS X*'

Dayo said:
One negative about simply running createinstallmedia is that the resulting bootable disk can only be used on units that support that Mac OS version. So, you cannot create a Catalina installer with createinstallmedia and run this on cMP.
Click to expand...
Right. It would have to be patched.
https://www.macrumors.com/how-to/install-macos-catalina-unsupported-mac/
https://forums.macrumors.com/threads/macos-10-15-catalina-on-unsupported-macs.2183772/

Dayo said:
The Install_USB_Maker script reconstitutes the installers after stripping the supported unit and other requirements such as certs out before creating the bootable disk (Legacy *.dmg Installers ... Lion to LoSierra) or dumping the ISO for burning (Modern *.app Installers ... Yosemite to Monterey). Such can then be used for installation via OpenCore for instance.

Will get round to extending the script coverage to Sonoma. Also, using dd for bootable disk creation was painful for the modern installers. So I decided to ditch this and ask users to use Etcher themselves. Will look at dealing with that later.
Click to expand...
I'm not sure I ever tried using OpenCore to boot an unpatched Catalina Installer on an unsupported Mac. I used the dosdude patchers from Sierra to Catalina for a Mac Pro 2008.
 
joevt said:
Not sure I ever tried using OpenCore to boot an unpatched Catalina Installer on an unsupported Mac
Click to expand...
Catalina was just an example chosen because it was the first that is not supported on any cMP ... which I wanted to use as an example unit type. The "2010 to 2020 era" units of the OP will not all be cMP or might not even include any.

The premise though, was that someone creating a multi-installer disk would want the option to be able to run such on as many supported/unsupported scenarios as possible. I suppose it could be that only supported versions would ever be installed and the limitation wouldn't matter but other readers might want to consider that angle.

I use OpenCore for unsupported Mac OS on my MP31 ... Tiger (thanks for helping with this) and LoSierra to Monterey with the exception of Catalina which is via a DosDude patched instance. DosDude Catalina serves as a "pseudo-natively-bootable" instance so that I can recover if needed without having to swap my RX580 out for HD5770.

I do not have a multi-installer disk of the kind discussed and just have the download packages from which I created uni-installer disks when I was installing Tiger to Monterey last year. Might be worth creating such a multi-installer at some point but saw the installation thing as more of a one-off at the time and on just one unit. OP seems to have a bunch of units and different calculations there.

Also already had OpenCore set up and as MyBootMgr creates one instance for installations/updates, I just created the boot sticks one by one and ran them as needed using OpenCore for the unsupported instances (apart from Catalina). With OpenCore, given my GPU and cMP models, I didn't need filesystem patches but will do so if/when I go beyond Monterey.

I suppose DosDude installers can also be used in a multi-installer stick for the relevant instances although I found the LoSierra to Mojave versions to be flaky when I went through the process last year. Not sure why as I had used DosDude HiSierra and Mojave without issue in the past. DosDude Catalina went smoothly. I always boot this one via RefindPlus.
 
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Dayo said:
I suppose DosDude installers can also be used in a multi-installer stick for the relevant instances although I found the LoSierra to Mojave versions to be flaky when I went through the process last year. Not sure why as I had used DosDude HiSierra and Mojave without issue in the past. DosDude Catalina went smoothly. I always boot this one via RefindPlus.
Click to expand...
True. A multi installer disk can include helper FAT or HFS+ partitions containing Dosdude booters, Open Core, RefindPlus, etc.
 
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