We all know and have at least once used the top(1) command on FreeBSD to track information about our cpu and processes, but how many of you know what each field means? By default, top(1) displays the ‘top’ processes on each system and periodically updates this information every 2.0 seconds using the raw cpu use percentage to rank the processes in the list.
This article will give you some insight on how to better understand top (1).
We’ve all been there: that moment of panic when a system fails to boot back up. Perhaps there was a glitch with an upgrade. Maybe you’re wondering if you fumble-fingered a typo when you made that last change to loader.conf.
Fortunately, with FreeBSD and its built-in rescue mechanisms it is possible to quickly recover from most scenarios that prevent a system from booting into normal operation. And if you’re using OpenZFS, you can rest assured that your data is intact.
With this article, let’s take a look at some common recovery scenarios.
If you are eager to start FreeBSD development, but don’t know where to begin, this short guide is for you.
This article will provide some pointers into how some FreeBSD committers work on the Operating System and ports collection. We will discuss the hardware configurations that are used day to day to implement, build and test the operating system.
In this article, we’re talking about the OpenZFS SLOG. Find out, among others, about synchronous vs asynchronous writes and the ZIL, why you should use a SLOG and on what type of devices.
Did you know that FreeBSD has more than one TCP stack and that TCP stacks are pluggable at run time? Since FreeBSD 12, FreeBSD has support pluggable TCP stacks, and today we will look at the RACK TCP Stack. The FreeBSD RACK stack takes this pluggable TCP feature to an extreme: rather than just swapping the congestion control algorithm, FreeBSD now supports dynamically loading and an entirely separate TCP stack. With the RACK stack loaded, TCP flows can be handled either by the default FreeBSD TCP stack or by the RACK stack.
Today, let’s talk a little bit less about technology itself, and a little bit more about business management. There are a couple of key management terms that every system administrator and IT professional should know and love—RPO and RTO, or Recovery Point Objective and Recovery Time Objective.
Once we understand the meaning and importance of RTO and RPO, we will take a look at two ZFS technologies—snapshots and replication—which greatly ease their management.
Understanding which data benefits from being in a snapshot and how long it makes sense to keep snapshots will help you get the most out of OpenZFS snapshots. Pruning snapshots to just the ones you need will make it easier to find the data you want to restore, save disk capacity, and prevent performance bottlenecks on your OpenZFS system.
While new protocols are constantly being developed, the venerable Transmission Control Protocol (TCP) still accounts for most global traffic. The FreeBSD kernel TCP stack offers a lot of opportunities to tweak different performance features. The options it includes allow a lot of flexibility in the configuration of machines without having to do custom kernel builds.
Find out how to make use of the Initial Window, what the TCP Segment OffLoad is, and how to use TCP Buffer Tuning to your advantage.
A ZFS boot environment is a bootable clone of the datasets needed to boot the operating system. Creating a BE before performing an upgrade provides a low-cost safeguard: if there is a problem with the update, the system can be rebooted back to the point in time before the upgrade.
This article demonstrates how to use the bectl utility to manage BEs and provides examples on how to update packages, apply security patches, and upgrade the operating system using BEs.
Let’s talk some more FreeBSD history. From the release of 4.3BSD to how networking for all became available and Net/1 and Net/2 came to be.
This article is going to cover the time period from the release of 4.3BSD with TCP/IP to the BSD lawsuits. This period set the stage for BSD as we know it today.