One day we’ll change some defaults to be more realistic, but in the meantime, please make sure you have set your FragmentLogFileSize and NoOfFragmentLogFiles to something big! Like, if you have 20Gb, set it the size to 256Mb and number of log files to 176, something like that (watch the diskspace though!). The thing his, if you need to restore your backup, you will run into problems and it just takes time, precious time to get it back up!
Anyway, those are not the only ones, and those hard hard to set later on (needs initial node restart, rolling though).
More in our all mighty manual and Johan’s configuration tool.