SMAPP and access path journaling

In addition to using system-managed access path protection (SMAPP), you can choose to journal some access paths yourself by using the Start Journaling Access Path (STRJRNAP) command. This is called explicit journaling.

To journal an access path explicitly, you must first journal all the underlying physical files. SMAPP does not require that the underlying physical files be journaled.

The reason for choosing to journal an access path explicitly is that you consider the access path (and the underlying files) absolutely critical. You want to make sure that the files are available as soon as possible when the system is started after an abnormal end.

Under SMAPP, the system looks at all access paths to determine how it can meet the specified target times for recovering access paths. It may not choose to protect an access path that you consider critical.

When the system determines how to meet the target times for recovering access paths, it considers only access paths that are not explicitly journaled.

How SMAPP is different from explicitly journaling access paths:

• SMAPP does not require that underlying physical files be journaled.
• SMAPP determines which access paths to protect based strictly on the target recovery times for all access paths. You might choose to journal an access path explicitly because of your requirements for the availability of a specific file.
• SMAPP continually evaluates which access paths to protect and responds to changes in your system environment.
• SMAPP does not require any user intervention to manage its internal journals and journal receivers.
• SMAPP uses less disk space for journal receivers because they are detached and deleted regularly.

For more information about when to journal access paths, see Reasons to journal access paths.