This would be a follow up to this closed thread: Bootable installer for High Sierra on SD … - Apple Community
Attached is the screenshot I get. I can't format the SD card with a partition format, it doesn't give me an option for volume scheme.
Any help would be appreciated!
MacBook Pro 13″, macOS 10.13
The error message seems quite clear. I think you are mixing things up here. If your goal is to install macOS to the SD card listed, then you must first use Disk Utility to erase the whole physical SD card as GUID partition and MacOS Extended (Journaled). Once you do this, the SD card will appear as a valid destination option for installing the full macOS to it.
A very important question is how much storage space does that SD card contain if you want to have a full working macOS installation on the SD card? You need to have enough space for macOS, your apps, your data, and at least 20+GB of Free storage space available at all times. Keep in mind booting macOS from an SD card will most likely be slow and underwhelming even if all these conditions are met. Most people find the smallest Apple SSD of 120GB to be much too small for macOS unless you are just using the laptop to do only the simplest things with very little data being stored.
Currently it appears the SD card contains the macOS High Sierra installer. If it was properly created using the instructions in the following Apple article, then you will need to boot from the USB installer by Option Booting the Mac so you can select the macOS installer from the Apple boot picker menu. Option Booting is when you press & hold the Option key immediately after hearing the startup chime. The macOS USB installer will not show up in the Startup Disk System Preferences.
Create a bootable installer for macOS - Apple Support
Also, Macs can be particular about the drives used for booting.
The error message seems quite clear. I think you are mixing things up here. If your goal is to install macOS to the SD card listed, then you must first use Disk Utility to erase the whole physical SD card as GUID partition and MacOS Extended (Journaled). Once you do this, the SD card will appear as a valid destination option for installing the full macOS to it.
A very important question is how much storage space does that SD card contain if you want to have a full working macOS installation on the SD card? You need to have enough space for macOS, your apps, your data, and at least 20+GB of Free storage space available at all times. Keep in mind booting macOS from an SD card will most likely be slow and underwhelming even if all these conditions are met. Most people find the smallest Apple SSD of 120GB to be much too small for macOS unless you are just using the laptop to do only the simplest things with very little data being stored.
Currently it appears the SD card contains the macOS High Sierra installer. If it was properly created using the instructions in the following Apple article, then you will need to boot from the USB installer by Option Booting the Mac so you can select the macOS installer from the Apple boot picker menu. Option Booting is when you press & hold the Option key immediately after hearing the startup chime. The macOS USB installer will not show up in the Startup Disk System Preferences.
Create a bootable installer for macOS - Apple Support
Also, Macs can be particular about the drives used for booting.
You have to follow the instructions to the letter. ...and think what you want to do. Install High Sierra to the Mac's internal disk or to some external disk or SD card (SD cards do work but are not good as real SSD's for booting)?
Did you Option-boot from the SD card? Did you then use Disk Utility to format the desired target SD card or SSD as APFS (GUID) case insensitive, MacOS Extended (GUID) is much faster if the target is a HDD?
Then switch to that High Sierra installer.
These are the options it gives me. I selected Mac OS Extended (Journaled) and then I got the error message from the first post. I'm trying to see if I can use hardware that I have available, if the SD card doesn't work, then I'll be getting a USB drive or getting the hard drive case so that I can connect my internal SSD as an external drive. I know I'm trying to save $10, so if I can't solve this quickly, I'll just go ahead and order the extra pieces I need. Thanks!
LOL doesn't Work on my iMac 2017 Ventura.
Bootable installer for High Sierra using an SD card
