svn has no command to clone a whole repository. If you have direct access to the repository on the server, you can just copy the whole tree or you could write a script that reads the log, checks out every revision and commits them to a new repository.
If you just want to keep a repository of your own patches which can be synced with the master svn server, I found that git-svn is a good solution. It can "clone" a svn repository into git and later you can later fetch updates from the svn master.
