Out of memory errors on S2. Safe to delete all dumpstate files?
Data in "log directories" should generally be safe to delete, as they are mainly intended for debugging purposes. The files having an .tar.gz extension simply means they are archived (see: tar (computing) at Wikipedia); if you copy them to your computer for investigation (e.g. using Winzip on a Windows machine, or the command-line tar xzf &lt;filename&gt;) will probably show those files contain *.log files.

If you want to be on the safe side, make a backup first. But I very much doubt you'll ever need those files again.