Keith's Ramblings…

So Drupal was becoming a bit of a pain for just running a simple blog. Really overkill and it lacked a lot of nice features I see on a lot of other blogs. Looking into those blogs I liked, they were all running WordPress. I’d stuck with Drupal because it supported PostgreSQL. But that feature alone wasn’t worth sticking with it anymore.

Got all my posts moved over, but still working on the old comments.

Still holding out hope that WordPress will add PostgreSQL support. Until then, guess I need to keep fresh on MySQL a bit longer. 🙂

No, I’m not a Minecraft player. I got into it for a little while during the Alpha, paid for the full client to support Mojang just because I thought the idea was fantastic and loved seeing what other people do. But I just couldn’t stick with it. I do, however, have several friends that are fanatical fans of the game and some cycles on the home server to spare. So I offered to host a server for them so they could all play together instead of their own single player clients at home.

One shortcoming that I had for a while with the Linux version was a way to do automated backups. When running Minecraft from the command line in a screen session, there was no way to automatically shut the server down cleanly without possibly causing world corruption. I hadn’t really been keeping up with the small updates in the backend coding, but apparently they finally added a “save-off” console command to the game to allow a clean backup of the world files while the game was still running. The next problem was figuring out how to send that to a screen session automatically.

Spent some time looking at the options in screen that I had never really had a need for previously so wasn’t familiar with them. The following is an example of the script I whipped up that will perform a full backup of Minecraft running in screen window 3.

screen -p 3 -X stuff "say Backup starting. World no longer saving!... $(printf '\r')"
screen -p 3 -X stuff "save-off $(printf '\r')"
screen -p 3 -X stuff "save-all $(printf '\r')"

cd ~/backups/
rm -f minecraft-low.tar.gz.old
mv minecraft-low.tar.gz minecraft-low.tar.gz.old
cd /path/to/minecraft/parent/folder
tar -cpvzf ~/backups/minecraft-low.tar.gz minecraft_folder

screen -p 3 -X stuff "save-on $(printf '\r')"
screen -p 3 -X stuff "say Backup complete! World now saving. $(printf '\r')"

The stuff command was the magic I was looking for. It sends some nice ‘say’ commands to the console to let any players online know that the backup is running and turns world-saving on and off to allow a good, clean backup to be taken. Took some hunting around the web to find a way to send a return character in a stuff command. Found several, but printf is the first one I came across that worked, so I went with it. I set this to run in my cron daily and my friends are now a little more thankful that their world is getting backed up more reliably than me just remembering to do it on occasion.