JucaRei

On another Debian (x86 or arm64, doesn't matter much).

apt install distrobuilder qemu-system-common

Create a configuration file (debian.yml for example) for your LXC image :

image:
  description: |-
    Nearly stock Debian Bookworm image

By default Linux distros are unoptimized in terms of I/O latency. So, here are some tips to improve that.

Most apps still don't do multi-threaded I/O access, so it's a thread-per-app which makes per-app speed always bottlenecked by single-core CPU performance (that's not even accounting for stuttering on contention between multiple processes), so even with NVMe capable of 3-6 GB/s of linear read you may get only 1-2 GB/s with ideal settings and 50-150/100-400 MB/s of un/buffered random read (what apps actually use in real life) is the best you can hope for.

All writes are heavily buffered on 3 layers (OS' RAM cache, device's RAM cache, device's SLC-like on-NAND cache), so it's difficult to get real or stable numbers but writes are largelly irrelevant for system's responsiveness, so they may be sacrificed for better random reads.

The performance can be checked by:

`fio --name=read --readonly --rw={read/randread} --ioengine=libaio --iodepth={jobs_per_each_worker's_command} --bs={4k/2M} --direct={0/1} --num

Here's how to use Home Manager without home-manager. @proofconstruction is my witness.

Getting the right version of Home Manager

First of all we have to make sure that the version of Home Manager matches the Nixpkgs release we want to use for our user environment configuration. Otherwise we will almost certainly get into trouble with mismatching interfaces.

We start out with a function that takes Nixpkgs as pkgs and fetch the appropriate Home Manager release. We get the given Nixpkgs version string from pkgs.lib.version and split it into the . format with lib.versions.majorMinor.

Installing Nautilus directly from Nixpkgs in Non-NixOS systems have no support for mounting sftps and other features that needs gvfs.

The solution for this is to install gnome3.gvfs in your packages list and then setup the env variable like this:

home.packages = with pkgs; [
  gnome3.gvfs
  gnome3.nautilus
];

Setting up qemu VM using nix flakes

Did you know that it is rather easy to setup a VM to test your NixOs configuration?

Create simple flake:

# flake.nix
{
  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";

OpenWrt 23.05.x Setup Under LXD 5.x on Debian 12 with PCI Passthrough

In case you missed it, Canonical relicensed LXD under AGPLv3 in December 2023 with a mandatory CLA. The LXD project was hard forked as Incus and licensed under an Apache 2.0 License.

Incus is maintained by the same team of developers that first created LXD and is recommended for new users going forward.

If you continue with this guide using Incus, substitute incus for lxc in each command.

Install `lxd` via `snap` and configure

💡 If using Debian 12 (Bookworm) or newer, you can just apt install lxd but keep in mind this pacakge is EOL and new users are encouraged to move to Incus.

Go to OpenWRT release page, select the latest release stable release, then targets -> x86 -> 64. Right-click generic-ext4-combined.img.gz (not the "efi"!) and copy the link.
On the Proxmox host, download the archive and unpack it:

wget *paste link here*
gunzip openwrt-*.img.gz

Resize the image to be the size you want your VM's disk to be (example with 8 GiB):

	#!/bin/sh

	#
	# FOR USE IN OPENWRT
	# This script creates a guest network fully isolated from the main one.
	# Tested on a Xiaomi AX3000T router; should work on any OpenWRT-powered router.
	#
	# - Ensure the Wi-Fi interfaces retain their default names (radio0 and radio1).
	# - For enable download/upload limits, install the sqm-scripts package on your OpenWRT router.
	#

	#!/bin/bash

	# Setting Up OpenWRT on a Virtual Machine with Proxmox
	# Based on: https://community.bigbeartechworld.com/t/setting-up-openwrt-on-a-virtual-machine-with-proxmox/257

	# Set your wished version:
	export VER="23.05"
	export ARCH="amd64"
	export INDEX_URL="https://images.linuxcontainers.org/images/openwrt/$VER/$ARCH/default"
	#export BUILDDATE=$(date -d "yesterday" '+%Y%m%d')

	{ localSystem ? builtins.currentSystem
	, crossSystem ? { config = "x86_64-unknown-linux-musl"; isStatic = true; useLLVM = true; }
	}:
	let
	# Fetch the nixpkgs-cross-overlay sources.
	src = builtins.fetchTarball "https://github.com/alekseysidorov/nixpkgs-cross-overlay/tarball/main";
	# Use the nixpkgs revision provided by the overlay.
	# This is the best way, as they are the most proven and compatible.
	nixpkgs = "${src}/utils/nixpkgs.nix";
	# Make cross system packages.