Admin sys

RAID1 array enlarging

Here’s a quick  recipe to easily enlarge a RAID1 array with the least possible downtime, using linux 2.6 and mdadm. We’ll start with a two-disk setup, /dev/sda and /dev/sdb, containing two arrays, /dev/md0 and /dev/md1. /dev/md0 is mounted on / and /dev/md1 is mounted on /backup. We want to grow /dev/md1 from 230GB to 898G…

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Registar switch

Back in may 2001, I grabbed my first domain name, colino.net. I wanted to stop switching URL each time I switched the hosting. At the time I had…

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How to change Dell’s BIOS settings from a Linux command-line

To be able to change BIOS settings from the command-line on a Dell Poweredge, you need the syscfg utility. It’s very useful when you want to change a configuration on, for example, 32 nodes at once, without having to plug screen, plug keyboard, reboot, change setting, reboot 32 times. Here is how I installed it…

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Lazily testing memory

I had, until recently, a problem when it came to test memory on the nodes in my lab. Until now, I was able to PXE boot memtest+, but had to go down to the lab and plug a screen to check the output. Multiple annoyances: first I had to move my ass to the lab…

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Stuff that happens to sysadmins

Buy one 1U server from $supplier, specifically ask for a pair of rails, learn that « Of course it comes with rails! ». Two weeks later. Buy a 42U rack, and eight 1U servers, all of these from the same $supplier, and at the same time. Receive your rack and 8 servers, without rails. Inquire by…

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