Ahhh .... Linux Multiboot help

[AstralTraveller (David)]

Experience: something you never get until just after you need it.

I've been a happy Linux user for years and generally find it better to use and manage than my work Window 7. I use LinuxMint; I previously used Ubuntu but moved away after they inflicted the Unity desktop on me - though now it also supports MATE so perhaps I should move back one day.

I've previously played with other distros in a multiboot setup but, now that I have the disk space, I want to trial a few more. I've installed elementaryOS (which looks it will become a major distro) and Astro (which turns out to be Mint with a modified GUI and heaps of astro apps pre-installed) but have had issues with openSUSE Leap 42.1 (it has an odd partitioning requirements and the USB stick may be suspect) so I'll leave it for a while.

What I've noticed before and what happened today is that the GRUB2 configuration used at boot resides in the most recently installed distro. Given that I plan to have distros come and go this is not appropriate. I want the GRUB2 configuration in my Linux Mint to be used. (I plan to keep Mint and it's well set up.) I've looked and looked but I can't find how to change the system to do that and to keep it that way. I've confirmed that the BIOS boots to the appropriate HD. That HD has a GPT partition table with a protective MBR and has a number of partitions called sda1, sda2, ... with one devoted to swap. Mint is on sda1.

I'm asking these questions here as it may avoid me having to join a Linux forum and also to avoid being told I don't know enough of the basics - I know I don't. Can anyone help - preferably with idiot-proof instructions.

[gary]

Hi David,

I gather you created a separate /boot partition?

Suggest you try the following -

Boot into the Mint OS distribution that you wish to configure GRUB2 from.

Run -
sudo /usr/sbin/update-grub2

This runs a script that in turn runs grub-mkconfig on the /boot/grub/grub.cfg file.

See man update-grub for details -
http://manpages.ubuntu.com/manpages/...te-grub.8.html

[gary]

Hi David,

By the way, as an aside, rather than using multiboot, have you considered
using a virtual machine environment?

Specifically, either Oracle VirtualBox, which is Open Source Software under the
terms of the GNU General Public License (GPL) version 2, or
the commercial VMware Workstation.

See https://www.virtualbox.org/
See http://www.vmware.com/au/products/workstation

If you do go that path, suggest you make the host machine (the one that
runs natively on the hardware and is running the virtual machine server),
a 64-bit distribution. That way, if you have more than 4GB of RAM,
you can exploit it over multiple virtual machines.

[bobson (Bob)]

You can use Boot Manager such as:

http://www.linux.org/threads/super-boot-manager.6073/

There are many other ones you can try. Its been a while since I played with different OS's

cheers

[BeanerSA (Paul)]

My preferred ways to play with Linux, are as others have said, with VirtualBox, or, I install GRUB (or whatever) into the same partition as I install /, and use EasyBCD to allow Windows to provide the boot menu. Makes it much easier to blow away distros when you are done.

[AstralTraveller (David)]

Hello again. It's been a while. I don't get much time in front of this computer and I've been a bit busy and a lot slack .

I'm aware of virtualisation, in fact that is how I run Windows. I've no interest in having Windows as my host OS and Linux as the guest. Running Linux in a box isn't what I need either.

Apart from wanting to tinker part of the reason for looking at other distros is the possibility of making them my main distro. I've considered this for a while but it got a kick along when I tried to connect a bluetooth keyboard under Mint. The GUI doesn't work and the fix looks to be a while away. (BTW I've since found a command-line method.) Also, if there was ever to be a big issue with, for example, all Ubuntu derived distros it would be nice to have a non_Ubuntu distro installed and ready to go. (My wife works mainly from home so if there is any down time I'm under the pump to fix it.)

Thanks to Gary for the specific suggestions. No, I don't have a separate /boot partition and no the command didn't work. I'm beginning to think these two facts may be connected and I do need a separate /boot partition. I've been reading a bit on booting Linux but so far haven't understood enough. But my confused look is coming along nicely. I've made the main distro the default in GRUB so it is now easy to start up - you can just turn it on and wait for the log on screen - and it's stable. So, when I think I have a plan I'll have another play, perhaps over the xmas break.

cheers,
David

[AstralTraveller (David)]

So, I finally did enough reading and got my head around this UEFI and GPT business. It's wonderful. You can now have as many partitions as you like without the 'work around' of extended and logical partitions! The boot process is no longer held together with sticky tape and string but feels solid and can be managed.

I presently have Mint, openSUSE and elementaryOS installed. By making sure the user(s) in each distro have the same UID and GID all my documents can be accessed and modified from within any distro, so if I decide I like one better than another changing over is easy.

I did a fair bit of reading but by far the most useful guide was here.
https://www.happyassassin.net/2014/0...lly-work-then/

[DarkArts]

You could create a small (eg. 5GB) partition to use as the master Grub partition and, optionally, a recovery partition ... with a bunch of tools pre-installed if you ever need them. As Gary says, you'll have to update it every time you install a new distro, but you'd have to do that somewhere anyway. Install a small/minimalist distro for that purpose.

I also use VMs for many programs - both Windows and Linux - running on a Linux host. One VM is pretty much dedicated to astro capture and processing. The best part (IMHO) is that I can experiment with anything and simply "revert to snapshot" if it stuffs up.