Defining devices for the OLDS
You configure the OLDS so that a system failure that renders an OLDS inaccessible does not stop the entire system. If you define dual OLDS logging, define each data set in an OLDS pair on different devices and, if possible, on different control units and channels.
The following figure shows an OLDS configuration with multiple devices. In this configuration, if one device fails, you can still access the OLDSs on the other two devices. For example, if device B fails while logging to primary OLDS 1 and secondary OLDS 1, you can still use primary OLDS 1 as input to the Log Archive utility, and IMS continues logging using the next available pair of OLDSs: Primary OLDS 3 and Secondary OLDS 3. If both Primary OLDS 3 and Secondary OLDS 3 have not been archived, IMS continues logging with the next available pair, Primary OLDS 6 and Secondary OLDS 6. The primary OLDS steps from one device to the next and the sequence wraps around.
