Showing posts from August, 2012

10 things to know when starting out as a sysadmin

This post was inspired by Henrik Warne's post "Top 5 Surprises When Starting Out as a Software Developer". I thought it was a good idea to put together a similar list for sysadmins. I won't call them 'surprises', just 'things to know'. I found them useful when I started out, and I still find them useful today. I won't prioritize them either, because they're all important in their own way.

Backups are good only if you can restore them

You would be right to roll your eyes and tell yourself this is so obvious, but in my experience most people run backups regularly, but omit to try to restore from those backups periodically. Especially if you have a backup scheme with one full backup every N days followed by either incremental or differential backups every day, it's important to test that you can obtain a recent backup (yesterday's at a minimum) by applying those incrementals or differentials to the full backup. And remember, if it's no…

The dangers of uniformity

This blog post was inspired by the Velocity 2012 keynote given by Dr. Richard Cook and titled "How Complex Systems Fail". Approximately 6 minutes into the presentation, Dr. Cook relates a story which resonated with me. He talks about upgrading hospital equipment, specifically infusion pumps, which perform and regulate the infusion of fluids in patients. Pretty important and critical task. The hospital bought brand new infusion pumps from a single vendor. The pumps worked without a glitch for exactly 1 year. Then, at 20 minutes past midnight, the technician on call was alerted to the fact that one of the pumps stopped working. He fiddled with it, rebooted the equipment and brought it back to life (not sure about the patient attached to the pump though). Then, minutes later, other calls started to pour in. It turns out that approximately 20% of the pumps stopped working around the same time that night. Nightmare night for the technician on call, and we can only hope he retaine…