Priority Paging Is Not Needed With the New Solaris 8 Caching Architecture

The Solaris 8 operating environment introduces a new architecture for file system caching, which subsumes the Solaris 7 Priority Paging functionality. Do not set the system variable priority_paging in the Solaris 8 operating environment. Remove the variable from the /etc/system file when systems are upgraded to the Solaris 8 operating environment.

The new caching architecture removes most of the pressure on the virtual memory system that resulted from file system activity. As a result, the new caching architecture changes the dynamics of the memory-paging statistics, which simplifies the observation of system memory characteristics. However, several of the statistics report significantly different values. Consider these differences when you analyze memory behavior or set performance monitoring thresholds. The most notable differences are the following.

• The number of page reclaims is higher, which you should consider normal operation during file system activity that is heavy.

• The amount of free memory is higher because the free memory count now includes a large component of the file system cache.

• Scan rates are almost zero unless there is a shortage of system-wide available memory. Scanning is no longer used to replace the free list during normal file system I/O.