Novel approach - Is it possible ?

[PlaneAnimal]

Hello all,

A noob question : Is it possible to boot from a live USB and then operate (work from) a HDD or SSD ?

Let me explain, I have created a debian 9 - stretch live usb and can boot from it. Can edit code such as Java or browse the web, etc.
have also installed Stretch on an SSD and can dual boot with Windows. This works fine. Am wondering, is it possible to use a combination of
the two, that is boot the computer using the live USB an then "switch" to the SSD/HDD to the installation and work off of it. This way the USB
would only do the initial booting.

I know that different drives can be "mounted", that is not what I'm looking for.

This may seem needless and strange, but why not.

By the way I'm new to linux and such, what I know have learned doing the installs mentioned above. I'm not a programmer / software engineer
of any kind. So any help would be appreciated. I have searched the net and this forum ( what little possible) and have not turned up an answer.
Perhaps I'm using the wrong terms, maybe even its because I don't fully grasp what is going on, in any case, if someone can point me in the right direction.
My apologies if I haven't learned the correct terms yet.

Thanks to all

[bw123]

It's probably possible. I think linux can be setup as complicated as you want to make it. I don't see why you would want to boot to and create the live system, then undo the live system and work from the hd install, but yeh, like you said, "Why Not?"

One thing you might want to compare is the mount points when booting Live to the HD booted system. There are other things a live system do that I don't understand myself, and documentation is a little tricky to find.

https://wiki.debian.org/DebianLive/

Maybe look through some of the wiki might help.

[p.H]

What would be your use case ?
What do you call "initial booting" and at what stage would you "switch" to the system on the SSD/HDD ?

[golinux]

This thread discusses a similar use case but using an SD card to boot with a 'persistence' partition on a HDD. Might be some useful tips for you there.

[PlaneAnimal]

Thank you, bw123, p.H and golinux.

I looked over the links suggested, some good info. It looks like the article on dev1galaxy may be along the lines of what I'm looking for.

For now to answer p.H , I see it as a way to pre-select which OS to boot before powering up the computer. If I plug in the USB stick
the computer boots debian and switches to the SDD / HDD so I can run from there, store info , etc. If not the machine starts in win 7.
This may not be useful and yes the grub boot menu does just that, but its an idea to be explored.

Again thanks for the replies, I will check into the suggestions.

[p.H]

You don't need a live USB for this. All you need is to install GRUB on the USB drive.

[PlaneAnimal]

I see, so then the boot partition is on the USB and the root partition would be on an SSD ?

or something like that ! Need to try a few variations.

Thanks

[stevepusser]

I'm trying to figure what you want to do, and why. If I understand you correctly, what you want can be done by booting from a LiveUSB and then chrooting into an installed system on the machine's main drive, but I still can't understand why one would want to do that for work.

[p.H]

I initially thought about a chroot too, but IIUC the OP actually wants to run a bootloader on the USB then boot the Debian system on the HDD/SSD from there.

[pcalvert]

Have you installed, or are you planning to install, Debian on its own partition on the laptop's HDD/SSD? Or are you simply using the laptop's HDD/SSD for data storage?

[PlaneAnimal]

Actually, I purchased an SSD specificaly to load Debian. Its installed and running, that is to say grub2 in installed with the Stretch distribution and I can boot either operating system. It works. To further explain, I am thinking if possible to use the USB as a kind of pre-power on switch. In other words the decision which system to boot is determined by whether or not the USB dongle is plugged in or not. WHy? well no real good reason other than perhaps saving a few seconds of attention span while starting up the computer. Have not had the chance to research the suggestions already made, but will do some reading tonight..

[golinux]

My board gives me a list of boot options if I hit F12 at post. That might simplify your life a bit. Just choose the one you want and <enter>

[PlaneAnimal]

Yes, that works on mine as well.

[pcalvert]

If you install GRUB4DOS on the USB drive, you can use it to chainload GRUB2 on the SSD. To minimize the changes to the USB drive, you could copy the GRUB4DOS files to the USB drive without installing it into the MBR. You could then use Syslinux to boot the live system or chainload GRUB4DOS. Then, using GRUB4DOS, you could chainload GRUB2 and boot Debian on the SSD. You could even use GRUB4DOS to chainload Syslinux, in case you changed your mind and wanted to return to the live system's boot menu.

Phil

[PlaneAnimal]

Hmmm, something to look into GRUB4DOS.


Thanks for the heads-up

[p.H]

What is the benefit of using GRUB4DOS (which IIRC is based on the obsolete GRUB 0.9/1 aka GRUB legacy) over the regular and modern GRUB 2 provided by Debian ?

[golinux]

What is the benefit of using GRUB4DOS (which IIRC is based on the obsolete GRUB 0.9/1 aka GRUB legacy) over the regular and modern GRUB 2 provided by Debian ?

GRUB 2 is a bit of a bloated hairball. Legacy GRUB was knowable and easy to configure. GRUB 2 foreshadowed the complexity of systemd, GTK3 etc. These days "modern" means an opaque black box.

[p.H]

GRUB 2 is bloated, yes, but extra features come at a cost. I would not trade all the extra features of GRUB 2 for the alleged simplicity of GRUB legacy.

[pcalvert]

What is the benefit of using GRUB4DOS (which IIRC is based on the obsolete GRUB 0.9/1 aka GRUB legacy) over the regular and modern GRUB 2 provided by Debian ?

It's smaller, simpler, and much easier to use. Those characteristics make GRUB4DOS a better choice for use on devices like boot floppy disks and bootable USB flash drives.

[stevepusser]

I have GRUB 2 in MX Linux set to boot from the last booted entry if I don't touch anything, and I also have entries in it to boot Windows 10 or go to the UEFI setup if I want that were created automatically, so it has to be possible to do the same in Debian. But that stuff's voodo to me...I used GRUB Configurator to set the default boot option in a GUI, too.

I Imagine that you could add an boot entry in there using the UUIDs for the USB drive that would only work if it was plugged in, but I am still having trouble with exactly why.