William Desportes williamdes

Proxmox with LVM-thin and why we should use Trim/Discard

Excerpts from the Proxmox VE Administration Guide]

LVM normally allocates blocks when you create a volume. LVM thin pools instead allocates blocks when they are written. This behaviour is called thin-provisioning, because volumes can be much larger than physically available space.

8.10.2. Trim/Discard It is good practice to run fstrim (discard) regularly on VMs and containers. This releases data blocks that the filesystem isn’t using anymore. It reduces data usage and resource load. Most modern operating systems issue such discard commands to their disks regularly. You only need to ensure that the Virtual Machines enable the disk discard option.

	#!/bin/env bash
	#
	# Filter the given tables out of a MySQL/MariaDB dump file.
	#
	#
	# The MIT License (MIT)
	#
	# Copyright © 2023 metaworx resonare rüegg, Martin Rüegg, Switzerland. All Rights Reserved.
	#
	# Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated

	-- Converts geohash (up to 12 characters) between text and bigint formats in Postgres

	-- https://dbfiddle.uk/UzF6gQzu

	-- The geohash length is stored in the 4 least significant bits,
	-- so that the relative order of the resulting int8 is the same
	-- as that of the the original text string:
	-- gzzzzzzzzzzz < h < h0 < h00 < h01 < h1
	-- -4 < 1 < 2 < 3 < 562949953421315 < 18014398509481986

	#! /bin/bash
	mkdir -p /var/cache/kerneltest

	#Make a file system image for the VM, and mount it.
	if [[ -e /var/cache/kerneltest/fs.img ]]
	then
	rm /var/cache/kerneltest/fs.img
	fi
	truncate -s 2G /var/cache/kerneltest/fs.img
	mkfs.ext4 /var/cache/kerneltest/fs.img

	I used this handy one-liner to search ip ranges while looking up its PTR record.
	The PTR record will have the string "stretchoid". This process took about an hour.

	for N in {128..255}; do echo "Testing 192.241.$N.0 - 192.241.$N.255" >> stretchoid_ips.txt; for L in {0..255}; do host -t PTR "192.241.$N.$L" \| grep -qF 'stretchoid.com.' && echo "192.241.$N.$L `host -t PTR \"192.241.$N.$L\"`" >> stretchoid_ips.txt; done; done

	Credit goes to sissy for the idea:
	https://forum.netgate.com/topic/169024/stretchoid-com-ip-list-for-use-in-blocking-their-port-scans?_=1671484145965&lang=en-US

	I then opened up the text file in notepad++ and did a regular expressions Search/Replace (CTRL+H)

	def pma_import_resubmit(br, sqlfile, target_dbname):
	""" To be used in phpmyadmin dump.sql file imports using python-mechanize
	as described in <https://github.com/phpmyadmin/phpmyadmin/issues/17423#issuecomment-1268271930>
	Only call this function when you have already found a 'timeout_passed=' string in browser response
	(so you are sure the page contains a resubmit link)
	"""
	# https://stackoverflow.com/questions/3569622/python-mechanize-following-link-by-url-and-what-is-the-nr-parameter/3569707#3569707
	#link = br.find_link(url = resumeurl)
	link = br.find_link(text = "resubmit the same file")
	link.absolute_url = link.absolute_url.replace("&","&").replace("?", "?db="+target_dbname+"&")

	#!/bin/bash

	trust="{1.1.1.1/32, 1.0.0.1/32, 8.8.8.8/32, 114.114.114.114/32, 114.114.115.115/32}"

	declare -A sets
	#sets["firehol2"]="https://iplists.firehol.org/files/firehol_level2.netset"
	sets["blocklist_net_ua"]="https://iplists.firehol.org/files/blocklist_net_ua.ipset"
	sets["firehol3"]="https://iplists.firehol.org/files/firehol_level3.netset"

	table_name="sink"

	<?php

	use Rector\Doctrine\Set\DoctrineSetList;
	use Rector\Symfony\Set\SymfonySetList;
	use Rector\Symfony\Set\SensiolabsSetList;
	use Rector\Nette\Set\NetteSetList;
	use Rector\Config\RectorConfig;
	use Rector\Php80\Rector\Class_\AnnotationToAttributeRector;
	use Rector\Php80\ValueObject\AnnotationToAttribute;

	# log4j jndi exploit CVE-2021-44228 filter
	# Save this file as /etc/fail2ban/filter.d/log4j-jndi.conf
	# then copy and uncomment the [log4j-jndi] section
	# to /etc/fail2ban/jail.local
	#
	# jay@gooby.org
	# https://jay.gooby.org/2021/12/13/a-fail2ban-filter-for-the-log4j-cve-2021-44228
	# https://gist.github.com/jaygooby/3502143639e09bb694e9c0f3c6203949
	# Thanks to https://gist.github.com/kocour for a better regex
	#