UEFI - how to install Fedora twice on same disk? (without breaking boot)

[interzoneuk]

Hi.

What is the proper way of installing Fedora twice on a UEFI disk.

I tried but whas not able to access the old install...

i.e can 2 Fedora installs share UEFI/EFI partition ?

I access UEFI from the computer's BIOS when I install Fedora it gives me as 'Fedora entry' from the bios UEFI boot selector - however if install a 2nd Fedora that takes its place (i can;t access old version)

Can anyone assist.

I think that UEFI is one of the worst things I have tried to work with...

[sea]

I think you mixed UEFI with GPT?

You mean beside setting up your harddisk for dual boot?

The 1mb bios_boot can be shared, just like an existing swap can be shared accros linux' of diffrent distros, or just as the one /home partitoin, to be used in all installations.

So the partitions could look like this:
1) bios_boot , 1mb
2) swap, 2048 mb
3) /home, 200gb
4) root-fedoraA, 32 gb
5) root-fedoraB, 16 gb
6) root-debian, 12 gb
7) root-slackware, 8 gb
...
..

[srs5694]

There are analogous issues for doing multiple installs of one OS on either BIOS of EFI. In the case of EFI, you'll have to do one of two things:

• Install the boot loader (GRUB Legacy, in the case of Fedora, although you can use another boot loader for one or both installations if you like) twice, but place each one in its own subdirectory of the ESP's EFI directory. The default name is EFI/redhat, IIRC, so you could use that for one and EFI/fedora for the other. AFAIK, the GUI installer doesn't give you an option to do this, so you'll need to do it manually. You'll then use the firmware's boot manager or another boot manager (such as rEFIt or rEFInd) to choose between them.
• Install one copy of GRUB (or whatever boot loader you opt to use) and configure it to boot both installations directly. This approach might work automatically, depending on the GRUB configuration scripts. Since you're posting about it, though, it seems it's not working, at least not for you -- or perhaps something else is going wrong.

If you need more help, I recommend you download and run the Boot Info Script from an emergency system. This will produce a file called RESULTS.txt. Post it here, either as an attachment or between code tags. The RESULTS.txt file contains information on partitioning and boot loaders (although its EFI boot loader information was minimal, the last time I checked it).

[interzoneuk]

Thanks for the responses.

Although I am generally confused about UEFI/EFI/GPT I am sure I have installed in UEFI mode...

I actually completely wiped my disk then this time setup Arch linux (using archboot iso) in UEFI mode first, then setuo Fedora afterwards in UEFI mode - i added another EFI partition

i.e

1 1049kB 3146kB 2097kB BIOS_GRUB2 bios_grub
2 3146kB 540MB 537MB fat32 UEFI_SYSTEM boot
3 540MB 1379MB 839MB ext2 ARCHLINUX_BOOT legacy_boot
4 1379MB 11.9GB 10.5GB linux-swap(v1) ARCHLINUX_SWAP
5 11.9GB 159GB 147GB ext4 ARCHLINUX_ROOT
6 159GB 159GB 210MB fat16 EFI System Partition boot
7 159GB 159GB 524MB ext4
8 159GB 213GB 53.7GB ext4

- partitions 6,7+8 are used for Fedora 17. - the others for Arch

I used to just install grub to various partitions and chainload to select them pre UEFI - which seemed a whole lot easier....

At present I'm using my System firmware boot manager - how do you remove an entry (I have 2 X arch linux) - if I could rename one then I could easily install another Fedora version without effecting the original one.

[srs5694]

You only need one ESP, no matter how many OSes you install. The EFI spec says you can have more than one, but Windows tends to get confused by this, and it's entirely possible that some other OSes (perhaps including some Linux distributions) would do the same. Thus, I recommend sticking with just one ESP. Make it FAT32, too, unless you have weird problems with files not being found or the like. (Some EFI implementations seem to have problems with FAT32, although the spec says it's required for the ESP.) OTOH, if you remove your second ESP without copying its files to the first ESP, you could end up with one or more unbootable OSes. If you transfer any files, you may need to modify your NVRAM settings with efibootmgr, too (see below).

Your first partition (a BIOS Boot Partition, identified by the "bios_grub" flag) is unnecessary unless you want to boot in BIOS mode. It does no harm per se, although the defaults for efibootmgr (see below) assume the ESP is on the first partition, so removing the BIOS Boot Partition and renumbering so that your first ESP is /dev/sda1 will make using efibootmgr a little easier.

You can modify the entries in your firmware's boot manager by using the efibootmgr utility in Linux. Check its man page for details. I've written a brief overview here (scroll to the last section on the page).

You can chainload from one GRUB to another one under EFI much as you would under BIOS, although the configuration details differ. (I speak theoretically; I've never actually bothered to try it this way.) Alternatively, you can use the firmware's boot manager or, if that's awkward, use rEFIt or rEFInd, which are add-on EFI boot managers. Note that rEFIt is Mac-centric and hasn't been updated in two years, so it's sub-optimal for use on a UEFI PC. rEFInd is my fork of rEFIt that includes bug fixes and new features to help with UEFI and Linux. Note that rEFInd can load kernels with EFI stub loader support (3.3.0 and later kernels) without using GRUB or any other boot loader. This can help simplify your configuration.

Since you're using Arch as one of your distributions, you may want to check its wiki. It's got some good documentation on EFI, such as its main page on UEFI.

[interzoneuk]

thanks for the responses