cmdln.org (a sysadmin blog)

Today Citrix announced that it will distribute its enterprise packaging of Xen for free. This brings fancy gui management and features available in VMwares ESX server to everyone. (Actually I’m not clear if just the ability is there or if they actually are letting the gui go as well.)

This is not a scaled down, limited version of the hypervisor. From the end of March on, there will be only one edition of XenServer which and it will be free.

The ability to manage multiple hosts via XenCenter, live migration via XenMotion, and resource sharing pools are all included in this free release.

Read the press release here.

I can’t wait to see what VMware does in response.

Have you ever gotten a pdf with one of those annoying passwords? A while back I bought an e-book and it came with a password. Its really annoying especially if I want to read it on a mobile device. Anyway if you are annoyed as much as I am fear no more.

Install qpdf

aptitude install qpdf

Decrypt your pdf

qpdf --password=password --decrypt input.pdf output.pdf

Over the last couple days I’ve briefly talked about revisioning configs and making your home directory portable. It seems to have stirred up a bit of discussion over at Matt Simmons Standalone Sysadmin, and Hugh Browns mentioned he uses mercurial for this task.. As I noted in the post about managing /etc with version control I do revision my home directory, or at least pieces of it. (more…)

Seems like we are on a bit of a roll with regard to the topic of versioning lately. Yesterday Legooolas commented about using version control for your home directory. I do and I’ll cover that in a different post but I use it for a different task. Now on to todays topic.
Do you keep track of configuration changes? You should. Maybe your using an advanced configuration management system like puppet. Even if you are you should keep your puppet configs versioned.
At any rate etckeeper is a great tool to version your configuration files stored in /etc. etckeeper hooks into your package manager and updates the repo each time changes are detected.
Its super easy to setup. In a debian based system just install via apt.

sudo aptitude install etckeeper

Once etckeeper is installed you need to initialize the git repository and do the initial check in.

sudo etckeeper init
sudo etckeeper commit

Every time I have a new shell account I end up customizing it. Making alterations to my vimrc, screenrc or whatever. It can be a huge pain when you have lots of slightly varying configs on different machines. I wrote this little script to grab my files and create a self extracting shell script so I can easily setup my environment on multiple machines. (more…)

Waddya know I’m not the only geek with an affinity for the console. This could be interesting. Repository of useful one liners.

Yesterday I wrote about CPU Performance Analysis in Linux. I explained how to tell if you are experiencing a CPU bottleneck. This is just a quick followup to show the effect of adding more cpu power. (more…)

A while back I wrote a post Analyzing Linux System Performance and Finding Bottlenecks. I did’t really give a good explanation of determining if you are CPU bound or not so I am writing this post to clear that up. (more…)

Have you ever experienced hard lockups and seen no trace of the cause in your log files? Those situations can be even more of a pain if you do not have physical access to the machine since you will not be able to look for kernel oops on the console. You could buy a serial console or an ip kvm but if you don’t have the need for remote control, but would really like to be able to debug without being physically present you need to check out netconsole. Netconsole sends printk messages over UDP. (more…)

Ever run into a situation where passing the option single to the kernel wasn’t enough to get your root password reset? This is not Debian specific but some distros (including Debian) require that you still enter the root password when booting to single user mode. This is just a quick run through of how to reset your root password without a live cd. (more…)