Multipath blocking mdraid

I have a system running CentOS 5.5 with 26 drives from Western Digital.

Online resizing with multipath and lvm

Here is a walkthrough on how to add more disk space to a system using multipathing and LVM without needing any downtime. In addition to showing the commands necessary to perfom the capacity expansion it is intended to show how, even if you didn’t know how the storage on a server was set up, you could figure it out. It assumes you’re using RHEL5 and a filesystem mounted on a device from a SAN that has more space available. In this example, I want to resize /u02 on a system named eserver.

Why powertop is awesome

I recently got a new, off-brand replacement battery for my Inspiron 1420 laptop. I used it for the first time today and was shocked to see the charge go from 100% to 10% in about 50 minutes while I was writing some emails. No noteworthy processor or disk activity was evident in my system monitor applet. Just as I was about to write a negative review on Amazon, it crossed my mind to check PowerTOP. PowerTOP is a utility for viewing how much time an Intel processor is spending in various power-saving states and what processes are waking it up from idle. I discovered I had left a virtual machine running. It was stuck trying to PXE boot; while its actual use of processor time was minimal, it was causing around 3000 wakeups a second! Shutting this virtual machine down brought wakeups down to a more reasonable 250 per second. This highlights how important the power savings from idling are on a modern processor and how powertop can help diagnose problems that would be difficult to tackle with other tools.

Calendar of floss events in ga

UPDATE: I realized I was doing a bad job of keeping this calendar comprehensive and have stopped maintaining it.

I’ve started maintaining a calendar of events and volunteer opportunities around GA involving linux and other free software. I’m currently subscribed to the ALE, CHUGALUG, LUG@GT, GA State’s Students for Open Source, GA Ubuntu LoCo, Atlanta “Pragmatic” Linux Meetup Group, and Free IT Athens mailing lists. I’m also subscribed to the LCLUE, MGALUG, SAVLUG, ATLOSUG, and OSSAtlanta rss feeds. Please leave a comment if you know of other places I should monitor for events or have an event you want publicized. Here are links to the calendar html, xml, and ical formats.