Expert Oracle Exadata - Parent Directory

CHAPTER 5 EXADATA SMART FLASH CACHEMonitoringYour options for monitoring ESFC are limited on the database servers. There is only one statistic relatedto ESFC in v$sysstat and related views (cell flash cache read hits). The storage servers, however,provide a much larger array of diagnostic information via the cellcli utility. Unfortunately, since thesemetrics are provided by cellcli on individual storage cells, they are limited to that single storage server.There is no comprehensive set of diagnostic information that covers the entire storage grid at this point.At the Storage LayerThere are a number of statistics that are captured for ESFC usage at the storage cell layer. The cellcliutility allows us to view those metrics. The LIST METRICDEFINITION command provides a description ofthe various statistics that are collected. For example:CellCLI> LIST METRICDEFINITION attributes name, description WHERE objectType = 'FLASHCACHE'Table 5-1 shows the output of the command. The table provides a brief description for each statistictracked at the storage layer that you can report on.Table 5-1. Flash Cache Metric DefinitionsMetricFC_BYKEEP_OVERWRFC_BYKEEP_OVERWR_SECFC_BYKEEP_USEDFC_BY_USEDFC_IO_BYKEEP_RFC_IO_BYKEEP_R_SECFC_IO_BYKEEP_WFC_IO_BYKEEP_W_SECFC_IO_BY_RFC_IO_BY_R_MISSFC_IO_BY_R_MISS_SECDescriptionNumber of megabytes pushed out of the flash cache because of space limit for'keep' objectsNumber of megabytes per second pushed out of the flash cache because ofspace limit for 'keep' objectsNumber of megabytes used for 'keep' objects on flash cacheNumber of megabytes used on flash cacheNumber of megabytes read from flash cache for 'keep' objectsNumber of megabytes read per second from flash cache for 'keep' objectsNumber of megabytes written to flash cache for 'keep' objectsNumber of megabytes per second written to flash cache for 'keep' objectsNumber of megabytes read from flash cacheNumber of megabytes read from disks because not all requested data was inflash cacheNumber of megabytes read from disks per second because not all requesteddata was in flash cache135