The XADVANCE command applies updates to the secondary volumes of an XRC session to a time that is consistent with the volumes of other sessions that are coupled to the master session. This is the same time to which an XRECOVER command updates secondary volumes of a session, except that the XADVANCE command does not cause the secondary volumes to be named with (clipped to) the primary volume volser. The XADVANCE command is used to advance all secondary volumes for all coupled sessions to a consistent time. When the XADVANCE function has completed, a copy of the secondary volumes can be taken with data that is consistent to this time.