Which files should I backup for data restoring/data migration?

[孔嘉林]

Hi,
I want to backup the files needed for data restoring/data migration. There
are several directories:
/var/lib/cassandra/
                   - commitlog/
                   - data/
                        - mytable/
                        - system/
                        - system_traces/
                   - saved_caches/
/var/log/cassandra/

So if I want a new machine start cassandra service on having the old data,
which of the files are needed? Is only the
"/var/lib/cassandra/data/mytable/" directory enough? Or I should copy all
of the above files on the new machine?

Thanks very much,
Joy