The tool used to ssh in parallel is http://code.google.com/p/csshx/

Nice. For OS X users, iTerm/iTerm2 "Send Input to All Tabs" mode (⌘-I) is another way to go about that.

Terminator (http://www.tenshu.net/terminator/ - not to be confused with http://software.jessies.org/terminator/) can group terms similarly on systems with gtk.

For linux users this is the equivalent: https://github.com/duncs/clusterssh

sudo brew install csshx

Note that deb and rpm packages are available, too.

http://wiki.apache.org/cassandra/DebianPackaging http://rpm.datastax.com/

How do you secure the ring? Should you use iptables so that only the other 3 hosts are allowed on the cassandra port? That seems like a bit much.

You can either allow traffic between one or more subnets, or put gossip traffic on a private network.