Ben benleb

This systemd service files can be used to launch a single kea instance on a server.

This requires that the config files are located under /etc/kea/ and the config files themself match this pattern:

dhcp4 server: kea-dhcp6.conf
dhcp6 server: kea-dhcp4.conf
ddns server: kea-ddns.conf
ctrl agent: kea-ctrl-agent.conf

You can name them differently but then have to adjust the service files accordingly

You might want to read this to get an introduction to armel vs armhf.

If the below is too much, you can try Ubuntu-ARMv7-Qemu but note it contains non-free blobs.

Running ARM programs under linux (without starting QEMU VM!)

First, cross-compile user programs with GCC-ARM toolchain. Then install qemu-arm-static so that you can run ARM executables directly on linux

If there's no qemu-arm-static in the package list, install qemu-user-static instead

Not happy with Docker modifying your precious firewall rules?

Docker inserts iptables rules when it's started by default
buster uses nftables by default
let's make Docker use nftables instead
PROFIT

Prerequisites

Install Docker CE and nftables:

To see current swap usage

sysctl -a | grep swap

Use only when when your system is in a very bad shape

$ sudo pkill -HUP -u _windowserver

To create a exFat partition which is compatible with all operating systems, I recommend using a drive with under 2TB. This will allow you to use an MBR partition table instead of GPT, I've had issues mounting GPT exFat drives in Windows.
This could be partially because I don't know how to Windows anything.

List Disks

fdisk -l

Mine for example is /dev/sdl, because I have many disks.

Overview

Syncing an Ethereum node is largely reliant on latency and IOPS, I/O Per Second, of the storage. Budget SSDs will struggle to an extent, and some won't be able to sync at all. IOPS can roughly be used as proxy of / predictor for latency. Measuring latency directly is arguably better.

This document aims to snapshot some known good and known bad models.

The drive lists are ordered by interface and then by capacity and alphabetically by vendor name, not by preference. The lists are not exhaustive at all. @mwpastore linked a filterable spreadsheet in comments that has a far greater variety of drives and their characteristics. Filter it by DRAM yes, NAND Type TLC, Form Factor M.2, and desired capacity.

For size, 4TB is a conservative choice which also supports a Fusaka "supernode". The smaller 2TB drive should last an Ethereum full node until at least sometime 2026, with [pre-merge history expiry](http

	# Collection of one line text art (◕‿◕✿)

	Collection of emojis and one line text art like (╯°□°）╯︵ ┻━┻ 🤗

	ּבּ_בּ
	טּ_טּ
	כּ‗כּ
	לּ_לּ
	מּ_מּ
	סּ_סּ

	#!/bin/bash
	#
	# This script reads the correct MAC address of a Jetson Nano from the onboard EEPROM over i2c.
	# First install i2c-tools package. Then make this script executable, and run it with sudo:
	#
	# $ sudo apt-get install i2c-tools
	# $ chmod +x nano-read-mac.sh
	# $ sudo ./nano-read-mac.sh
	# MAC address is xx:xx:xx:xx:xx:xx
	#

	# My ISP-provided fiber optical modem broadcasts a line of a poem every ten seconds. Here's the tcpdump of the complete poem.
	# The optical modem is made by Shanghai Nokia-Bell Co.,Ltd and its model number is G-140W-UD. It's provided by my ISP, China Unicom in Shenzhen.

	$ tcpdump -i vlan10 ether proto 0x8300
	15:59:00.720301 00:00:00:00:00:12 (oui Ethernet) > Broadcast, ethertype Unknown (0x8300), length 72:
	0x0000: 0000 0000 e4ea 8386 d93c 5468 6520 6461 .........<The.da
	0x0010: 7920 4920 6c6f 7374 206d 7920 7665 7279 y.I.lost.my.very
	0x0020: 2066 6972 7374 2074 6f6f 7468 2c00 0000 .first.tooth,...
	0x0030: 0000 0000 0000 0000 0000 ..........
	15:59:10.740778 00:00:00:00:00:12 (oui Ethernet) > Broadcast, ethertype Unknown (0x8300), length 72:

	import asyncio
	import aiohttp
	import time


	async def gather_with_concurrency(n, *tasks):
	semaphore = asyncio.Semaphore(n)

	async def sem_task(task):
	async with semaphore: