Live Backup of Minecraft

I use Minecraft on Linux,¬†occasionally¬†I find java crashes whilst I’m playing and I lose my world save. I think it has more to do with some buggy hardware currently than the OS after a discussion I had with someone in meatspace.

Anyway, yeah, no matter what’s at fault, losing a Minecraft world is no pleasant thing, so I created the following script to incrementally backup whilst I’m playing. I run it from my home directory:

#!/bin/bash

# Live backup of the game for java crashes
# Author: Wes Fitzpatrick

if ! [ -d .minecraft_live_backup ]; then
 cp -pr .minecraft .minecraft_live_backup
fi
if ! [ -d .minecraft_current_session ]; then
 cp -pr .minecraft .minecraft_current_session
fi
mv .minecraft_live_backup .mc_last_session`date | awk '{ print $1 $2 $3 $4 }'`
while true; do
 rm -fr .minecraft_current_session && cp -pr .minecraft .minecraft_current_session
 sleep 120
 rm -fr .minecraft_live_backup && mv .minecraft_current_session .minecraft_live_backup
done

What this does is first backups up your current .minecraft folder, so your last game is preserved, then creates two alternate backups. One is your current (minecraft_current_session) up to the last 2 minutes of play, the second is the previous current (minecraft_live_backup) in case the failure occurs during backup.

I’ve tested the backup copies and both work in event of a crash. This means rather than losing the entire castle, I’ve only lost the last few block placed.