Notes on Zenoss ZenPacks

Recently I was building a ZenPack for Zenoss. The ZenPack included an Event Command which executed a custom script. I wanted to store the custom script in the ZenPack and I didn’t want to do anything other than have proper script dependencies in place for it to work. (Read More)

Analyzing I/O performance in Linux

Monitoring and analyzing performance is an important task for any sysadmin. Disk I/O bottlenecks can bring applications to a crawl. What are IOPS? Should I use SATA, SAS, or FC? How many spindles do I need? What RAID level should I use? Is my system read or write heavy? These are common questions for anyone…

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Transparent dynamic reverse proxy with nginx

A while back I wrote about using Apache as a dynamic reverse proxy. Anyone who has done even minimal research into web servers knows that Apache is the swiss army knife. It trys to be everything for everyone, and like a swiss army knife may not be as good as a more refined too at…

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Analyzing linux system performance and finding bottle necks

System performance analytics seems to be a frequent question on forums and mailing lists. Finding out why something is slow is generally nontrivial as there are many factors to consider. I have found the sysstat package to be an invaluable tool when looking at system performance. Specifically the command sar gives a wealth of information….

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