Previously (in Magnolia <4.5) XMLFileSplitter could be used to split large bootstrap files. It uses a hard coded reference to the mgnl:content nodetype to split the file into chunks.
However, in Magnolia 4.5 pages use the new nodetype mgnl:page, which is why XMLFileSplitter cannnot be used anymore for data exported from Magnolia 4.5. As it's impossible to load large XML files into Magnolia/Jackrabbit without splitting the files, this is a crucial functionality in backup/restore scenarios.

Please make the nodetype configurable on command line and please also put some minimal documentation somewhere on how to use this tool, something like this:

FYI: this is how it can be executed:
java -cp WEB-INF/lib/magnolia-module-backup-1.2.2.jar:WEB-INF/lib/commons-io-1.4.jar:WEB-INF/lib/xercesImpl-2.8.1.jar:WEB-INF/lib/commons-lang-2.4.jar info.magnolia.module.backup.ie.XMLFileSplitter [folder containing files to split]
Use the restore script from the Magnolia Wiki (toolsv4_1.jsp) to import the generated files, this way the nodes' order is preserved.