I have Cassandra 0.8.0 running with data on server 1, and a clean install of Cassandra 1.0.3 on server 2.
Is it possible to just copy some files from server 1 to server 2? Or do i have to write my own import/export code?
Both servers can be taken down, restarted, etc.
Why would you not upgrade server1? Upgrade details here (either way read this first): http://svn.apache.org/viewvc/cassandra/branches/cassandra-1.0/NEWS.txt?view=markup
But if you do want to change machines, follow the procedures for 'nodetool snapshot' as detailed here: http://wiki.apache.org/cassandra/Operations#Backing_up_data
Re-create the schema on the new node, then add the snapshots to the data directory (as described above), restart cassandra then issue a nodetool scrub.