~$ svnsync help initialize
initialize (init): usage: svnsync initialize DEST_URL SOURCE_URL

Initialize a destination repository for synchronization from
another repository.

The destination URL must point to the root of a repository with
no committed revisions. The destination repository must allow
revision property changes.

If the source URL is not the root of a repository, only the
specified part of the repository will be synchronized.

You should not commit to, or make revision property changes in,
the destination repository by any method other than ‘svnsync’.
In other words, the destination repository should be a read-only
mirror of the source repository.

Valid options:
–non-interactive : do no interactive prompting
–no-auth-cache : do not cache authentication tokens
–username ARG : specify a username ARG (deprecated;
see –source-username and –sync-username)
–password ARG : specify a password ARG (deprecated;
see –source-password and –sync-password)
–trust-server-cert : accept unknown SSL server certificates without
prompting (but only with ‘–non-interactive’)
–source-username ARG : connect to source repository with username ARG
–source-password ARG : connect to source repository with password ARG
–sync-username ARG : connect to sync repository with username ARG
–sync-password ARG : connect to sync repository with password ARG
–config-dir ARG : read user configuration files from directory ARG
-q [--quiet] : print as little as possible

~$ rpm -q –whatprovides $(which svnsync)
subversion-1.6.2-1.el5.rf