8.1 Storage management in IZB in 1999 As described earlier, in 1999 IZB was running two data centers, one located in Munich and one in Nuremberg. PPRC Mirroring was only used for production data at that time, because IZB determined that moving the tapes to the disaster recovery location hundreds of miles away would only be feasible if an actual disaster struck. That is, an outage of just a storage controller or a tape robot would not be sufficient to declare a disaster and experience all of its consequences. For an overview of IZB's previous environment, read 1.2, "From 1999 until now" on page 5. 8.2 Description of the situation This section outlines IZB storage management before the relocation project. For a description of the site arrangement, read 1.2.1, "Two data centers, 160 kilometers apart" on page 5. DASD environment In 1999, the DASD environment was a collection of different vendors and mirroring concepts. There were Amdahl and EMC storage controllers without mirroring installed. Some Hitachi storage controllers with PPRC mirroring were installed in the data centers in each site. Each DASD controller had different features and performance characteristics. Additionally, some DASD was shared between development and production systems, which required a great deal of attention from the storage management team; it was somewhat challenging to run two DFHSM systems that did not know each other on the two systems sharing DASD. Figure 8-1 illustrates the DASD configuration at Munich at that time.