On Wed, Dec 07, 2022 at 04:42:05PM -0800, Adam Williamson wrote:

Hi folks! Today I woke up and found https://bugzilla.redhat.com/show_bug.cgi?id=2151495 , which diverted me down a bit of an "installer environment size" rabbit hole.

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Why does this matter? Well, the images being large is moderately annoying in itself just in terms of transfer times and so on. But more importantly, AIUI at least, the entire installer environment is loaded into RAM at startup - it kinda has to be, we don't have anywhere else to put it. The bigger it is, the more RAM you need to install Fedora. The size of the installer environment (for which the size of the network install image is more or less a perfect proxy) is one of the two key factors in this, the other being how much RAM DNF uses during package install.

Is there something that can be done to optimize the RAM usage, in spite of the large installer env size ?

If we're installing off DVD media, it shouldn't be required to pull all of the content into RAM, since it can be fetched on demand from the media. IOW, 99% of the firmware never need leave the ISO, so shouldn't matter if firmware is GBs in size [1] if we never load it off the media. Same for languages, only the one we actually want to use should ever get into RAM.

If we're installing off a network source, we need to pull content into RAM, but that doesn't mean we should pull everything in at once upfront.

Is it possible to delay pulling in non-NIC firmware until we have a NIC configured, and just rely on the basic generic framebuffer setup by UEFI/BIOS until we get far enugh to pull in video card firmware ?

For localization, is it possible to split the localization into per-language bundles, and delay loading off the network until we know what language we want to load, instead of pre-loading all languages ?

With regards, Daniel

[1] Yes, I know it matters for user media download size in reality