Installation Specification

[hamishmb]

Okay, so apparently your comment in the document passed me by Patrick, sorry about that. I don't make any attempt to make Debian match the packages installed in Raspbian by default because I considered that to be irrelevant. I suggest we remove that section entirely to make it simpler for future maintainers, as it adds a lot of complexity and requires a fair bit of knowledge of how package management works.

Thoughts?

[TerryJC]

Hamish,

You've lost me. Who are you responding to and about what? Did you post this in the wrong place?

[hamishmb]

Oops, wasn't very clear.

Patrick left a comment in the Installation Spec to do with creating the Pi VMs, and I'm responding to that comment.

[hamishmb]

At any rate, I'll upload my changes now, as a WIP document.

These include removing unneeded sections of the instructions for the Pi VMs, as well as changing the default paragraph style to Liberation Sans instead of Liberation Serif. Sans fonts are much easier to read for those with dyslexia, and I personally find it a lot easier as well.

[PatrickW]

Hamish, having discussed this with you in person today, I agreed that it is probably not necessary to customise the package installation to quite the extent specified in the document, and that avoiding doing so makes the instructions easier to follow.

However, be careful about simply removing the entire section regarding Debian package selection without reviewing the implications for the rest of the annex. Really, the only way to tell what the implications are in full is to closely follow the resulting new instructions and build a VM image, to see if they still work without that block of text.

I can see one problem straight away, though:

Earlier in the annex, it says to configure *no* swap partition in the Debian installer, based on the assumption that you will subsequently install dphys-swapfile to make it more like Raspberry Pi OS. But you have removed the instruction to install dphys-swapfile. Some kind of swap space will be necessary. I'd suggest sticking with dphys-swapfile, as we know that works. If you go with a swap partition instead of a swap file, then, when it says to add the discard option to the root filesystem, it will also need to say to add the discard option to the swap partition, and this will need testing to make sure the VM disk image still shrinks when swap space becomes unused.

As for the other packages I listed for installation in the removed block of text, I can't say whether they are necessary without trying to build another VM without them.

[hamishmb]

Yeah, as you say, I'll test them before removing the WIP suffix.

I'm not sure we will need more RAM to be honest, I don't think I configured a swapfile or swap partition for any of the VMs I made before, but I will check and try it and then report back.

[PatrickW]

The default Debian installation has a swap partition, so whatever you do you will end up needing some kind of instruction about swap configuration, whether that's to remove the swap or to change it to a swap file or to add the discard option to the default swap partition.

It seemed an easy enough configuration to emulate the RAM and swap of the actual hardware, in the hope of surfacing any bugs that were specific to that, so I just did it.

Based on experience, I imagine that the system does take advantage of the swap file when it is present, if only during the installation. There is a difference between "takes advantage of" and "needs", though, so my wording "will be necessary" was probably a bit strong.

[hamishmb]

Yeah, that's fair enough. I'll try it with no swap and see how it goes.

[hamishmb]

For reference, so I can merge the changes with my WIP version, does Iss 0.17 of the Installation Spec just add the missing mariadb dependency?

[TerryJC]

There was one minor typo fix as I recall, but it shouldn't give you a problem. I accepted all the proposed changes from before.

If you do a diff on the two docs, the changes will show up.