Smokeping monitor your network latency SmokePing keeps track of your network latency: Best of breed latency visualisation. Interactive graph explorer. Wide range of latency measurement plugins. Master/Slave System for distributed measurement. Highly configurable alerting system. Live Latency Charts with the most ‘interesting’ graphs. Free and OpenSource Software written in Perl written by Tobi Oetiker, the creator of MRTG and […]

rdiff-backup What is it? rdiff-backup backs up one directory to another, possibly over a network. The target directory ends up a copy of the source directory, but extra reverse diffs are stored in a special subdirectory of that target directory, so you can still recover files lost some time ago. The idea is to combine […]

Tcp dump tip   Capture package from host x.x.x.x on interface eth0 tcpdump -i eth0-n src host x.x.x.x tcpdump -vv -ni eth0 port 1514 -w tcpdump -vv -ni eth0 port 1514 -w ./capture.cap   Tcpdump usage examples October 1, 2014 In most cases you will need root permission to be able to capture packets on an […]

Systemd crash course, with remote logging he world is taking systemd by storm and there is no looking back now. Still, there are some elements that you would expect to be there that are missing. One of them is remote logging! Another thing missing is a decent crash course [*]. This is frustrating because making init scripts and checking logs is the […]

Vim Cheat sheet Cursor movement h – move cursor left j – move cursor down k – move cursor up l – move cursor right w – jump forwards to the start of a word W – jump forwards to the start of a word (words can contain punctuation) e – jump forwards to the end of a word E – jump forwards to the […]

Basic how-to for LSYNCD Welcome back to my ever-increasingly-inaccurately-named How-to Trilogy In this how-to, I’m going to explain how to set up a basic lsync replication. WHAT IT IS: lsync uses rsync to automate the replication of files from one server (the “master”) to one or more servers (the “slaves”). I could spend a long time explaining how rsync […]

Installing GlusterFS – a Quick Start Guide Purpose of this document This document is intended to give you a step by step guide to setting up GlusterFS for the first time. For this tutorial, we will assume you are using Fedora 21 (or later) virtual machines (other distributions and methods can be found in the new user guide, below. We also […]

Block lever HA with DRBD DRBD refers to block devices designed as a building block to form high availability (HA) clusters. This is done by mirroring a whole block device via an assigned network. DRBD can be understood as network based raid-1. In the illustration above, the two orange boxes represent two servers that form an HA cluster. The boxes contain the usual components of a […]

What’s a quick way to comment/uncomment lines in Vim? o comment out blocks in vim: press Esc (to leave editing or other mode) hit ctrl+v (visual block mode) use the up/down arrow keys to select lines you want (it won’t highlight everything – it’s OK!) Shift+i (capital I) insert the text you want, i.e. ‘% ‘ press Esc Give it a second to work. To uncomment blocks in vim: […]