If you’re like me you probably have an environment that is running on some virtual platform and like everyone else you have built a template to spin Linux systems. One of the things lately we were running into was the “70-persistent-net.rules”, which associated MAC address to Network interfaces. The easiest way I have found to…
System Administration
Work Blog: Managing Your Linux Deployments with Spacewalk
I have been using Spacewalk for a while now and really like a lot of the built-in functionality. I have been using it to build out and manage a lot of my Red Hat, and CentOS installations. The latest thing I have been using it for it to manage is my Hadoop cluster build out…
What does Facebook consider an average day's worth of data?
Well according to this article from gigaom.com. The average day looks something like this. 2.5 billion content items shared per day (status updates + wall posts + photos + videos + comments) 2.7 billion Likes per day 300 million photos uploaded per day 100+ petabytes of disk space in one of FB’s largest Hadoop (HDFS)…
CentOS 6.4 service virt-who won't start – work around
Here is the problem. [root@bob ~]# service virt-who start Démarrage de virt-who : Traceback (most recent call last): File “/usr/share/virt-who/virt-who.py”, line 33, in <module> from subscriptionmanager import SubscriptionManager, SubscriptionManagerError File “/usr/share/virt-who/subscriptionmanager.py”, line 24, in <module> import rhsm.connection as rhsm_connection ImportError: No module named rhsm.connection [FAILED] There is a simple work around. Install the Scientific…
Hadoop to Hadoop Copy
Here recently I need to copy the content of one hadoop cluster to another for geo redundancy. Thankfully instead of have to write something to do it, Hadoop supply a hand tool to do it “DistCp (distributed copy)”. DistCp is a tool used for large inter/intra-cluster copying. It uses Map/Reduce to effect its distribution,…
Amazon Relational Database Service (Amazon RDS)
It appears that Amazon is introducing a new service specifically targeted at Relational Databases helpful hints. You can choose from MySQL, Oracle, and Microsoft Sql Server. Amazon Relational Database Service (Amazon RDS) is a web service that makes it easy to set up, operate, and scale a relational database in the cloud. It provides cost-efficient and resizable capacity while managing time-consuming…
Using Iozone for Filesystem Benchmarking
If you have been around computer systems long enough everyone knows how import disk performance is, espeacially with database systems. There’s the standard htparm -tT and dd test the everyone does, but it really does give you the whole picture. What you really want is to test read, write, re-read, re-write, read backwards, read strided, fread,…
Install Git From Source On Linux
If you are like me and want to install git-core core from source instead of one to the many binary packages out or you just have a distro that does have a binary for it. Here is what you will need to get it installed. POSIX-compliant shell GCC – gnu c compiler GNU Interactive Tools…
Using CURL to manage Tomcat
The other day I and a few of my colleges were talking about a easy way to deploy and undeploy war files from the command line like you could through the Tomcat Web Application Manager portal and being on a python kick, I started writing it in python. After an hour or two I realized that…
Simple HTTP Server with Python
Ever needed a quick web server to share something with a Windows user from you Linux box. Python has really easy to use embedded HTTP Server. Just try the following.shell> python -m SimpleHTTPServer 9001 And point you web browser at http://localhost:9001 and see what happens. — Cheers