# Multiboot question



## debs3759 (Jun 18, 2020)

I want to set one of my systems up with multiple OS. I want to be able to boot MSDOS, Windows, Linux, FreeBSD and try out a few hobby / experimental OS. Part of my reasoning is that I want to test writing code that can be cross assembled/compiled.
I'm thinking that DOS and Windows will be on one drive, Linux and BSD on a second, and everything else on a third.

Can someone either walk me through how to achieve this, including what boot managers can do this and what order to install the various OS, or direct me to a reliable website with a detailed guide?

The top two links in the pinned post are no longer working, so I can't check what they have to say. I have only ever used DOS and Windows, but want to experiment in particular with Linus and BSD while also having Windows available for benchmarking my collections.


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## sam_86314 (Jun 18, 2020)

I would probably just run them in VMs.

If you absolutely need to run them on bare metal, I'd think GRUB would work for that.


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## DrCR (Jun 19, 2020)

Install *nix options last. Anything non-hardcore should automagically do GRUB magic for you as part of the installation process.


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## silentbogo (Jun 21, 2020)

I'm also in favor of trying out stuff in VMs. Running all of those OSes natively on modern hardware limits your options, and with that "diverse mix" it's a perfect trap for newbie to mess up a boot drive.
If you really-really want to run them natively, why not do it off live USB? Just use Windows on your main machine, and get a 32-64GB stick where you can use YUMI Multiboot to put everything else (it even supports persistent partitions for most Linux distros). 
Another alternative on Win10 is WSL(Windows Subsystem for Linux). It's not perfect, but enough to get you a functional testing platform. 
Both WSL and HyperV will give you the advantage of being able to test your code right away.


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## debs3759 (Jul 7, 2020)

Thanks for the replies. I don't want to use VMs as I won't get maximum performance if I have the overhead of running two OS at the same time. Might just opt for removable drives with a caddy on newer systems and CF-IDE adapters on older systems if I can't get the multiboot working easily.


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## Vya Domus (Jul 7, 2020)

debs3759 said:


> I don't want to use VMs as I won't get maximum performance if I have the overhead of running two OS at the same time



An operating system in a VM will run it's own separate kernel as if it was native, there is no real overhead, in other words the performance will be the same. Of course if you do something demanding on either one of them performance will degrade but that's expected. The only real limitation is 3D acceleration.

I've screwed up my system multiple times multibooting different OSes so I gave that up, I stick with VMs now.


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## DrCR (Jul 7, 2020)

debs3759, as Vya notes, there's risks, which is always the case. But unless you choose the wrong partition and overwrite your Windows partition when installing, or some such, you can almost fix things. I've never once been unable to fix something I've borked, but I once did make use of a safety net. Safety net examples would be to backup your partition table and the like e.g. sfdisk -d /dev/sda > sdapartitiontablebackup.txt and dd if=/dev/sda of=sdambrbackup.txt bs=512 (MBR drive).

Basically I'm trying to say don't be scared of a multi-OS install. I'll also note though to not be quick to dismiss the VM route. The multi-OS route is what I use on my home computers. I like it's simplicity. For my workstation in the office, I'd only use VMs.

Side note: You want to have a backup plan in place regardless. If your OS drive borks, that should not be more than annoyance. If you don't have a backup setup, something simple, even just manually run before doing multi-OS stuff, would at least be a good first step e.g. a /usr/local/bin/backupscript that has rsyncs for the dirs of interest. Spending just a minute on such an inelegant setup could be prudent.


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## biffzinker (Aug 2, 2020)

I just installed Linux Mint on spare SSD a couple of days ago. I unplugged my two other drives to prevent any drives from being altered. The GRUB boot loader is on the spare drive with Linux Mint install.

The only hang up I’ve ran into involves Secure Boot. I missed the chance on first boot to enroll the key so signed drivers load. At the moment I’ve just disabled Secure Boot.


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## cat1092 (Aug 2, 2020)

Whatever one does in a multiboot system which includes Windows, be sure to make a full disk image of that OS & it's other partitions first. Except Data, if on another drive.

This can be done with Macrium Reflect Free Edition, there's also a choice under 'Other Tasks' to include a boot menu for ultra fast backups, restores & clones. Be sure to also create an ISO, save on an external for when needed (I have a folder for these).

Doing it like this, if something goes wrong, can get back to normal fast. Be sure to have a spare small USB drive or SD card and a USB card to use it with (what I use all of my old small SD cards for), can use Rufus, a small & separate download, to make a bootable drive from the saved ISO. Do this before installing Linux or other OS's.

I backup my systems every week, plus the day before Patch Tuesday, and keep the first & last three backup images taken.

Cat



biffzinker said:


> I just installed Linux Mint on spare SSD a couple of days ago. I unplugged my two other drives so the GRUB boot loader is on the spare drive with Linux Mint install.
> 
> The only hang up I’ve ran into involves Secure Boot. I missed the chance on first boot to enroll the key so signed drivers load. At the moment I’ve just disabled Secure Boot.


That's OK, I don't use nor recommend Secure Boot anyway!

Don't know of the first person whom Secure Boot protected, if it were that great of a feature, the sections of many Tech forums where infections are handled wouldn't be a mile long.

When I work on computers for others, the first thing I do is disable Secure Boot. And if the person has a notebook, also open CMD as Administrator & type *powercfg -h off *, this makes the computer truly shut down when finished. If running a SSD, the way Windows installs in a semi-hibernation mode, this wears it out by creating tons of writes, every SSD optimization guide will say so. Lastly, being never shut down, kills the battery. One can feel the bezel near the power switch hours after 'turning off' (not shutting down) & it's still very warm to the touch. I've seen using HWMonitor where after only a year, 25-30% of the battery's original life is shot.

And I charge nothing for these services. Just want to see the folks who relies on me to have longer lasting computers.

Cat


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## oinkypig (Aug 2, 2020)

create partition. the partition will get a drive letter. open cmd as administrator. type in bcdboot D:\Windows /addlast /d  (replace D: with drive letter) and bootup will give you options at bootup


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## DrCR (Aug 2, 2020)

Cat, I haven't run WinOS at home for many years now, but the next time I build a gaming rig and have to dive into non-enterprise Win10, I'll have to remember some of your WinOS backup thoughts.



cat1092 said:


> And I charge nothing for these services. Just want to see the folks who relies on me to have longer lasting computers.


That's bold. Free service now means expected free service 5 years from now.


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## GoFigureItOut (Aug 5, 2020)

It's possible. I haven't used multiple disc to contain several OSes, so I'm at a lost. You might be able to get some help from the guy that runs *dedoimedo.com. On his laptop, he has an eight-boot set up. Its probably all on one drive (assuming since most laptops only have one bay).*


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## Cicom (Aug 24, 2020)

DrCR said:


> I'll have to remember some of your WinOS backup thoughts.


This is necessary.


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