Question

14

How to add a GRUB2 menu entry for booting installed Ubuntu on a USB drive?

rated 0 times [ 14] [ 0] / answers: 1 / hits: 160805 / 2 Years ago, thu, january 13, 2022, 3:57:40

I am not asking how to boot the LiveCD from a USB.

I have 2 Ubuntu installations, one on my computer's internal hard drive and another on a USB drive.

Is there a way to add a GRUB2 menu entry (to the GRUB on my internal hard drive) to boot the Ubuntu OS which I have installed to the USB flash drive and have this same menu entry still work after I've upgraded the Linux kernel on the USB installation?

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utonmbo

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2 Years ago

answered 2 Years ago splenueak · Accepted Answer

I found out how to use the UUID of the drive, useful if you have multiple drives plugged in at boot time. Credits to oldfred for his note about /vmlinux and /initrd.img symlinks.

Add this to the file /etc/grub.d/40_custom, replacing UUID=XXXX-YYYY with the partition UUID (get UUID with command blkid)

menuentry "Boot from USB Drive" {

    set root=UUID=XXXX-YYYY

    linux /vmlinuz root=UUID=XXXX-YYYY ro quiet splash

    initrd /initrd.img

}