Linux

what are the disadvantages of using a shared home (yes with a shared profile, I still want to access my Steam library from Arch if I want that)

Well, a disavantage I can think of is that if your apps are in different versions, it may be messy. Also, if you share a DE between both environments, it also may become messy

Why don't you try using only one system and see what happens?

Another thing that concerns me is GRUB, usually when I’m dualbooting with Windows, the Linux distro takes care of the grub stuff, should only a single distro take care of GRUB? or I need to install “the grub package” on both? Do both distros need separate boot partitions? Or a single one for a single distro (like a main distro) will suffice?

Only one system taking care of grub, pls. Grub is already a pain, don't make it even more painful. If you're going to config grub, let PopOS handles it. Only install it after Arch and everything should be fine

If it does not recognize Arch, you may wanna enable os-prober at grub conf, but that's it

Another off topic question, my HDD is partitioned to oblivion, can I safely delete ALL partitions? Including the EFI one? I’m not on a MacBook, a typical 2014 Toshiba that’s my laptop

If you're ok with losing all the data, it's okay to wipe out everything and let the distro install itself alone

I have a triple boot laptop with MX Linux, Void Linux, and OpenBSD on an old laptop where VMing wouldn't work so well.

As others have pointed out a shared home directory is not a good idea. Shared data (documents, music, images, etc.) would be fine as mentioned previously.

@notTheCat @linux I haven't tried this but I think a shared boot partition and one installation of grub (I suppose the version you like the most, if you have a preference). You might even want to install grub from neither and do it by hand, just to make sure they won't mess it up. About shared home: not sure. It will work - I just don't know how many little oddities there will be.

EFI partition can be deleted and re-created.

Why bother with Pop!_OS when you’re comfortable with Arch? Arch is, in my opinion, better for gaming just due to its newer packages, and certainly its newer Kernel. I’ve been running EndeavourOS which is basically just pre packaged Arch, and it handles all of my gaming and productivity tasks more to my liking than any Ubuntu based distro, certainly better than Pop! did.

Also, I see no reason why you shouldn’t delete all of your old partitions and start fresh, but when you do, give EndeavourOS a whirl and see if it handles all of your dev tasks and gaming. I think you’re over complicating your system and not getting any tangible return from dual booting Pop!

With plain linux that's a bit complicated to actually dualboot. When booting windows grub just throws the ball to windows bootloader and it manages things from that on, but with grub you'd need to have two separate grub-installations on different partitions so that changes made in Arch doesn't mess up stuff with PopOS (and other way round). It's very much doable, but I suppose (without any experience on a setup like that) that if you just go with default options it'll break something sooner or later and you need to pay attention to grub configs on both sides at all times, so it requires some knowledge. Basically you'd need a grub installed on (as an example) /dev/sda for the system to boot from bios and another grub instance at /dev/sda5 (or whatever you have) for second grub. They'd both have independent /boot directories, grub configs and all the jazz. It's doable, but as both systems can access either one of the confgurations you really need to pay attention on what's happening and where.

Mixing home directory with different distros can create issues, as things have slightly different versions of software and their underlying philosophy, specially when mixing different package managers, is a bit different and they might not be compatible with eachother. Personally I would avoid that, but your mileage may vary wildly on how it actually plays out.

For the partitioning, you can safely delete all the partitions, but you'll of course lose the data on the drive while doing it.

If I'd need such a system I might build a virtual machine to run all the dev stuff and just connect to it from a "real" desktop environment. Essentially mimic a two separate systems where you'll have a "server" for the dev things and a "desktop" to connect with it. Or if you want a clear separation between the two it's possible to run a different window manager for each of the tasks and just logout/login to switch between the two and with some scripting/tweaks you can even start/stop services as required when you switch between "modes". Depending on your needs it might be enough just to run development environment with a virtualbox and start/stop it as needed and adjust the actual desktop experience accordingly.

You just want to prove that it works, right? Otherwise it doesn't make sense. It's all linux. Pick one and you're good to go.

As an alternative suggestion, you could use bazzite (atomic fedora built for gaming) and add an arch compartment for coding stuff.

Bazzite just runs games out of the box, it's soooo convenient.

As others have mentioned, just stick to one distro (and I recommend Arch, since you're already familiar with it - also, it's much better for gaming compared to Pop).

If you really want to have that delineation between dev stuff and gaming, you could just create a separate gaming user account, and even do cool stuff like automatically launching Steam in big picture mode, or take it a step further and jump straight into a gamescope session.

Why not use the same, and for example isolate your gaming in Bottles Flatpak, or in a Distrobox?

That would be my first honest recommendation.

Then the problems with a shared home are that you may have different DEs and app versions writing config files in there. They may override each other (GNOME and KDE always do that) or just be incompatible between versions.

You might instead consider having two separate user accounts with separate home directories, with symlinks for each to /home/shared or whatever (such as ln -s /home/shared/Downloads ~/Downloads for example.) Much less likely to go wrong in horrible ways.

If you really want to tripleboot Linux, I highly recommend systemd-boot, especially because you are already using Arch, which supports it. I'm sure you could get it to work with Pop.

I was dualbooting 2 Linuxes for a long time. All that you need is to install GRUB once on one of the distros, but having two or more bootloaders in the same EFI System partition is generally harmless, and might happen due to how some distros' installers are written. In that case the BIOS boot order will decide which one to use. Either way, you only need one boot partition.

It is safe to delete all partitions on your hard drive if and only if you have backed up any important data on them. It's basically the same as installing a new hard drive. The installer for your distro will be able to re-create all of them.

I have personally never used a shared /home between multiple distros, but based on my experience switching desktop environments, there are likely to be conflicts between files that lead to bugs. Arch and Pop!_OS will have vastly different versions of most software, and it's possible that changes to a config file in one distro may break the program in the other. Shared /home is better for if you have just one OS installed, and reinstall it occasionally.

The typical distro's installer will just take care of setting up GRUB for you, don't worry about that. I'm doing something similar with my home partition, except I made a home partition with all the expected user folders ~/Videos ~/Documents ~/Music ~/Games etc and then used overlayFS which keeps ~/.config/ and the like separate for each OS partition while letting me share everything else.

Not much point if your machine is reasonably up to date, just kvm whatever other distro you want.