SysAdmin

How YARN Changed Hadoop Job Scheduling

Scheduling means different things depending on the audience. To many in the business world, scheduling is synonymous with workflow management. Workflow management is the coordinated execution of a collection of scripts or programs for a business workflow with monitoring, logging and execution guarantees built in to a WYSIWYG editor.

The Growing Role of UEFI Secure Boot in Linux Distributions

With the increasing prevalence of open-source implementations and the expansion of personal computing device usage to include mobile and non-PC devices as well as traditional desktops and laptops, combating attacks and security obstacles against malware is a growing priority for a broad community of vendors, developers and end users.

Debugging Web Sites

I know, I'm in the middle of a series of columns about how to work with ImageMagick on the command line, but when other things arise, well, I imagine that a lot of you are somehow involved in the management of servers or systems, so you all understand firefighting.

DNSSEC Part II: the Implementation

This article is the second in a series on DNSSEC. In the first one, I gave a general overview of DNSSEC concepts to lay the foundation for this article, which discusses how to enable DNSSEC for a zone using BIND.

LVM, Demystified

I've been a sysadmin for a long time, and part of being a sysadmin is doing more than is humanly possible. Sometimes that means writing wicked cool scripts, sometimes it means working late, and sometimes it means learning to say no. Unfortunately, it also sometimes means cutting corners. I confess, I've been "that guy" more than once. A good example is SELinux.

Solid-State Drives: Get One Already!

I've been building computers since the 1990s, so I've seen a lot of new technologies work their way into the mainstream. Most were the steady, incremental improvements predicted by Moore's law, but others were game-changers, innovations that really rocketed performance forward in a surprising way.

DNSSEC Part I: the Concepts

Like IPv6, DNSSEC is one of those great forward-looking protocols that unfortunately hasn't seen wide adoption yet. Before I implemented it myself, I could see why. Although some people think BIND itself is difficult to set up, DNSSEC adds an extra layer of keys, key management and a slew of additional DNS records.

SIDUS—the Solution for Extreme Deduplication of an Operating System

SIDUS (Single-Instance Distributing Universal System) was developed at Centre Blaise Pascal (Ecole normale supérieure de Lyon, Lyon, France), where one administrator alone is in charge of 180 stations. Emmanuel Quemener started SIDUS in February 2010, and he significantly cut his workload for administering this park of stations. SIDUS is now in use at the supercomputing centre PSM

Protect Your Ports with a Reverse Proxy

In a previous article, I discussed Apache Tomcat, which is the ideal way to run Java applications from your server. I explained that you can run those apps from Tomcat's default 8080 port, or you can configure Tomcat to use port 80. But, what if you want to run a traditional Web server and host Java apps on port 80? The answer is to run a reverse proxy.

Two Pi R

Although many people are excited about the hardware-hacking possibilities with the Raspberry Pi, one of the things that interests me most is the fact that it is essentially a small low-power Linux server I can use to replace other Linux servers I already have around the house.

Advanced Hard Drive Caching Techniques

With the introduction of the solid-state Flash drive, performance came to the forefront for data storage technologies. Prior to that, software developers and server administrators needed to devise methods for which they could increase I/O throughput to storage, most of which resulted in low capacity caching to random access memory (RAM) or a RAM drive.

Manage Your Configs with vcsh

If you're anything like me (and don't you want to be?), you probably have more than one Linux or UNIX machine that you use on a regular basis. Perhaps you've got a laptop and a desktop. Or, maybe you've got a few servers on which you have shell accounts.

Fight the Good Fight with SmokePing

My Internet connection is unstable. I do realize ISPs generally claim some downtime is expected, and service is not guaranteed, and countless other excuses are common for intermittent service. I currently pay $120/month for business-class service, however, and I expect to get reliable Internet access on a regular basis.

Raspberry Strudel: My Raspberry Pi in Austria

I remember my first colocated server rather fondly. It was a 1U Supermicro that had been decommissioned from my employer after a few years' service. Although it was too old and slow for my company, the 800MHz CPU, 1GB RAM and 36GB SCSI storage was perfect for my needs back in 2005. A friend was kind enough to allow me to colocate the server at his facility for free.

Raspberry Pi: the Perfect Home Server

Ever since the announcement of the Raspberry Pi, sites all across the Internet have offered lots of interesting and challenging uses for this exciting device. Although all of those ideas are great, the most obvious and perhaps least glamorous use for the Raspberry Pi (RPi) is creating your perfect home server.