Lukas,

most of the files are simple text files.

Unpack the log file to some temporary directory.

All files older than the failing reboot obviously can be skipped

Most kernel message go into "dmesg", looking at an older log dump it looks to me that this file is rotated every 24 hours and upon reboot.

If the boot failed, I'd expect some errors or alike in the corresponding dmesg file.

If that gives no clues, it's up to your intuition to check the other files for messages that might hint at the failing component.

Of course, contacting the very friendly and helpful open-e support team with a copy of the log dump and a short error description might bring you forward, too.

With regards,
Jens