I am wading into Global Mirror for the first time, for a client interested in a 2-site disaster recovery solution, and it has been a challenge pulling "executive summary" details out of vendors and documentation.
The production site is a multiple-LPAR, basic sysplex with DS8000 DASD, for which the goal is a remote mirror at a site with compatible hardware including a backup CPU. The client wants to be able to test DR procedures multiple times per year. Management understands, and more to the point so do I, I think, the need at the remote end for twice as much DASD capacity as locally, in order to maintain a consistency set comprised of the two primary copies and a second, "Flashed" copy at the remote site. Up to now we have collectively believed that remote Flashcopy-maintained set of volumes could be used to IPL remotely for DR testing purposes, without disrupting the global mirror between the local and remote primary DASD. Enter once again the vendors, who are now telling us that we will need a *third*, flashed copy for this purpose, in order not to disrupt the global mirror during testing. My understanding (and the standard disclaimers apply here!) is that DR can be tested remotely without IPLing from a copy of the copy, details admittedly TBD. If true, that the remote DS8300 requires not two but THREE times the DASD as in production locally, can someone out there please digest for me an executive explanation I could use to justify the increased cost to management? Thanks in advance, Tom Sims "Feedback is a gift." ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
