Tom, If you are close enough, with enough bandwidth for Metro Mirror (syncronous), you only need one copy of the storage at the remote site and a 2nd copy if you want to do DR testing non-disruptively. If you are further away, and need to run Global Mirror (asyncrounous) the minimum you need 2x the storage at the remote site to maintain a consistency copy. Then if you want to do DR test *without* stoppping mirroring that will require a 3rd copy at the remote site.
Unless the vendor is Hitachi where their replication is journal based, they don't need the extra copy for consistency volumes. Dana ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
