Temporary dual boot with EFI (GPT) and MBR table possible?

I’m still using an old MBR partition table layout (without EFI) and would like to set up everything fresh on a second SSD, but I want to keep my original MBR SDD until everything is finished …
would this work if I disable legacy mode in the BIOS & create a new SSD with GPT and EFI so that my old MBR is still recognized and starts afterwards via EFI grub?

If you disable legacy mode, you won’t be able to boot the MBR drive anymore in most BIOSes.

However, as long as your BIOS supports a legacy+uefi mode it should work. Most modern desktop BIOSes do support this.

From there you would just need to use your BIOS to select the proper boot option.


This won’t be possible. Grub can only boot systems which are installed in the same mode. Switching between the systems will only be possible via firmware as @dalto mentioned.

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ok, just for migrating (rsync) my /home stuff … a new gpt eos installation is still be able to read from the old ssd if both drives are connected and started from the new gpt system?

Yes. MBR/UEFI only effects the booting process. Reading/writing won’t be impacted.

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