In a Sysplex environment, using the MVS System Logger provides the following advantages:

• Communication is faster and more efficient because the MVS System Logger communicates through the Coupling Facility.
• The MVS System Logger is a single, Sysplex-shared data set managed (that is, defined, accessed, and recovered) automatically by native MVS System Logger services.
• The MVS System Logger automatically writes to a duplex DASD staging data set to provide automatic saving of the data on failure-independent, persistent media.
• The MVS System Logger provides automatic recovery support if the system, Sysplex, or Coupling Facility structure fails.
• The MVS System Logger is not a wrap-around file and therefore cannot overwrite data.
• The MVS System Logger is an MVS-managed file that is automatically offloaded at pre-determined thresholds to DASD log data sets.
• The MVS System Logger never has to be reformatted and enlarged.

  Note: A Coupling Facility is a shareable storage medium. It is licensed internal code running in a special type of PR/SM logical partition. A Coupling Facility can be shared by the systems in one Sysplex only. It makes data sharing possible by allowing data to be accessed throughout a Sysplex with the assurance that the data will not be corrupted and will be consistent among all sharing users.