Gary, You can *ask* about best practice, but in this case no one can say what's universally best, not to mention what's best for you. I still think you got some answers and a few examples of what people are doing.
It depends on what events do you want to protect yourself against, how quickly do you want your system or its parts back online, how much of the most recent data are you prepared to lose, and how much can you pay. Answers to these questions can lead to DR strategies ranging from a crumpled piece of paper in your pocket to a spare HAL in the orbit (I'm sure he'd support z/VM if asked politely). With the prices of disk storage and comms channels going down, mirroring to another site gained in popularity, but that's certainly not an answer for everyone. With modern disk systems and their fancy features you can make snapshots during the day and be happy with that. All these things said above are, admittedly, as much of an answer for z/VM as for any other operating system. If you are concerned about software failures or failures of z/VM features, then you first need to know the administrative processes of each feature, and that will give you an idea about a recovery process. In general, tape or virtual tape or disk-to-disk backups are your best friends. If you are concerned about CMS application recovery, then checkpoints are your better friends. Nothing new here. Depending on the amount and type of checkpoint data, you may use GLOBALV command, TDISKs, VDISKs, dataspaces, spool files, messages to "master" virtual machines with databases, and many other ways to achieve this. I, and more knowledgeable people on this list, would really need more specific info from you. Ivica
