Systems Management Empire MIB › NT System Group › NT Performance Groups › NT Cache Performance Group
NT Cache Performance Group
The NT Cache Performance group contains system-wide buffer and file system cache statistics that let you determine the effectiveness of a system's caching mechanisms.
Class: ntCachePerf
When an application requests data, the data is first mapped into the cache and then copied into memory from the cache. Later, data changed by the application is written from the cache to disk by the Lazy Writer system thread or by a write-through call from the application.
Monitor the following cache performance information in this group to see if the cache is performing poorly (for example, if the system has a low cache hit ratio). If so, your system may need additional memory:
- Number of async reads from cache pages (ntAsyncCopyReads)
- Number of async data maps of file pages into the cache (ntAsyncDataMaps)
- Number of async MLD reads from the cache (ntAsyncFastReads)
- Number of async reads in preparation for writing the data back to disk (ntAsyncPinReads)
- Number of copy reads and copy read hits (ntCopyReads, ntCopyReadHits)
- Number of cache pages flushed and flush operations (ntDataFlushPages, ntDataFlushes)
- Number of data maps resolved without retrieval from disk (ntDataMapHits)
- Number of data maps resulting in pinning a page in main memory (ntDataMapPins)
- Number of data maps (ntDataMaps)
- Number of fast reads, failed fast reads, and fast read cache misses (ntFastReads, ntFastReadNotPossible, ntFastReadResoureMisses)
- Number of lazy write flushes and pages flushed (ntLazyWriteFlushes, ntLazyWritePages)
- Number of MDL cache reads and MDL cache read hits (ntMDLReads, ntMDLReadHits)
- Number of pin reads and pin reads that hit the cache (ntPinReads, ntPinReadHits)
- Number of reads that wait for copy operation (ntSyncCopyReads)
- Number of file system data maps (ntSyncDataMaps)
- Number of sync fast reads, MDL reads, and pin reads (ntSyncFastReads, ntSyncMDLReads, ntSyncPinReads)
