The usb flash installer is working as it should, but when trying to install on external usb drive (which is formatted as it should) then after first boot, my iMac simply start up normal. Not continuing the install. If I try to hold option when boot, I can only pick the usb flash installer and my internal drive.. I don't know how to continue.
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Problem install on external usb drive.. (problem solved)
- Thread starter ultradk
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hmm...
Are you booting to the USB installer, or just trying to run the installer app on that drive, while you are still booted to your internal drive?
So, restart, holding your Option key. Choose the usb flash drive to boot (not your internal drive)
If THAT only boots to your internal drive (your normal system), then I suspect that your USB flash is not created properly.
Did you follow the steps to use CreateIntallMedia to make the USB bootable installer?
If all that is really OK, keep in mind that some types of external USB drives will NOT allow a bootable system install. I have a Seagate 8TB Backup+ hub hard drive. Works great for backups/storage, but I cannot install a system on a partition on that drive - and make it bootable. It won't boot. I tried 4 or 5 different methods, but nothing will make that drive bootable.
What external USB are YOU using to make that bootable system?
Are you booting to the USB installer, or just trying to run the installer app on that drive, while you are still booted to your internal drive?
So, restart, holding your Option key. Choose the usb flash drive to boot (not your internal drive)
If THAT only boots to your internal drive (your normal system), then I suspect that your USB flash is not created properly.
Did you follow the steps to use CreateIntallMedia to make the USB bootable installer?
If all that is really OK, keep in mind that some types of external USB drives will NOT allow a bootable system install. I have a Seagate 8TB Backup+ hub hard drive. Works great for backups/storage, but I cannot install a system on a partition on that drive - and make it bootable. It won't boot. I tried 4 or 5 different methods, but nothing will make that drive bootable.
What external USB are YOU using to make that bootable system?
When booting to the usb flash, I choose it as startdisk. Then start installing as usual.
I did try createinstallmedia (has done it before), even diskmaker x and install disk creator, but same result.
It only takes 4-5 minuts before it's finish and boot the first (then go into my internal drive)
I am using Seagate 2 TB USB 3 drive and create a partition - 100GB should be fine for test running Hig Sierra. However, last time I tried with Mojave was on 1 TB Seagate USB 3 drive (with only 50GB) - does that say anything? Perhaps I should try with that drive.
I did try createinstallmedia (has done it before), even diskmaker x and install disk creator, but same result.
It only takes 4-5 minuts before it's finish and boot the first (then go into my internal drive)
I am using Seagate 2 TB USB 3 drive and create a partition - 100GB should be fine for test running Hig Sierra. However, last time I tried with Mojave was on 1 TB Seagate USB 3 drive (with only 50GB) - does that say anything? Perhaps I should try with that drive.
Read my post above. I have a Seagate Backup plus (8TB), and can install a system just fine. BUT, it won't boot to that system. I tried different methods, and nothing works. The Seagate Backup Plus won't boot a Mac.
Yes, if you have another Seagate drive that you could boot an older system, try that drive.
Or, even better, use any other USB drive that is NOT a Seagate brand.
Yes, if you have another Seagate drive that you could boot an older system, try that drive.
Or, even better, use any other USB drive that is NOT a Seagate brand.
I have Yosemite and Mojave on Seagate external drive.. Why not High Sierra?Read my post above. I have a Seagate Backup plus (8TB), and can install a system just fine. BUT, it won't boot to that system. I tried different methods, and nothing works. The Seagate Backup Plus won't boot a Mac.
Yes, if you have another Seagate drive that you could boot an older system, try that drive.
Or, even better, use any other USB drive that is NOT a Seagate brand.
However I try another disk..
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Yes, why not?I have Yosemite and Mojave on Seagate external drive.. Why not High Sierra?
However I try another disk..
You can do that by adding another partition to your Seagate external, like you have already done for Yosemite and Mojave.
If you have 2 boot partitions already, just add another partition. Use that new partition as the destination for a High Sierra install.