Setting up and maintaining Linux software RAID on an Apple Xserve G5 with Yellow Dog Linux

Despite certain frustrations with our Apple Xserve G5s, I’ve found that they make decent Linux servers, especially considering their age. Recently I wanted to repurpose one as a development server, and in that role I really wanted disk redundancy for added protection of the data. Unfortunately there’s no RAID controller in these servers, so software RAID is the only option. Originally RAID wasn’t crucial and I gave up on software RAID as it seemed too complicated to justify the time spent figuring out how to do it. This time, however, it was more important and I was determined to get software RAID functioning.

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Problems bundling EC2 volumes on Amazon Web Services to create images from running instances

I attempted to comment on this LOPSA blog entry about problems bundling EC2 volumes, but for some reason they haven’t approved my comment so I’m turning it into a blog entry here instead.

The problem is that sometimes, when attempting to make an image out of a running EC2 instance, the ec2-bundle-vol command fails for reasons that are not clear. This can be a massive nuisance because you might have made quite a few changes to a running instance which would take significant time to recreate on a new instance in order to make an image from it.

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System administrators in films

I recently watched Cargo (2009), which turned out to be a pretty decent sci-fi film (sort of a cross between Silent Running, The Matrix and Alien). One thing I particularly enjoyed about the film, however, was that a key member of the spaceship’s crew was a system administrator (and a female sysadmin at that!). I liked the way this character was important to the plot, and I was amused by the way the filmmakers gently poked fun at the geeky nature of sysadmins.

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New graphics card (ATI Radeon HD 4870) on my Mac Pro

When I started playing Bioshock on my ageing Mac Pro, I found that the graphics card (a Nvidia GeForce 7300GT, apparently) was so poor by today’s standards that the game was practically unplayable. I therefore decided to get a new ATI Radeon HD 4870 graphics card. Despite the fact that Apple say this card is for recent Mac Pros (Early 2009 or Early 2008), it works fine in my original Mac Pro (2006).

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Bash script for configuring specific things on users’ Macs

Although I’ve got our Mac mini server nicely set up now, there are occasionally things I want to do on users’ Macs which can’t be done or don’t work properly via Server Admin and Workgroup Manager. However, one of the wonderful things about having an office environment consisting entirely of Macs (rather than Windows PCs) is that you can just SSH into them and write Bash scripts which can be triggered by cron (or, better still, by launchd.

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Moving from cron to launchd on Mac OS X Server

As the usage of cron is now deprecated on OS X and OS X Server in favour of launchd, I thought it was about time I learnt how to use launchd so I could move all my cronjobs across to it. launchd is one of Apple’s various contributions to the Unix world, and its purpose is to be a single tool to take the place of init and to replace a variety of startup mechanisms such as the rc/rc.d startup architecture, cron, and inetd/xinetd. In keeping with most other technologies emanating from Apple it is simple, elegant, efficient and powerful. If you do a significant amount of Mac administration then now is the time to learn launchd if you haven’t already.

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