SmartIO uses a cache area on the SSD devices for caching. Each cache area has attributes such as the cache type, size, association type, the caching state, and the devices used for caching. The cache area also has associated data objects.
For a VxFS cache area, the sfcache list command shows the caching mode for the file or directory. If the mode is not explicitly set, the file or directory inherits the caching mode of the mount point. If the mode is explicitly set for a file or directory, that value persists across remounts. The displayed caching mode may differ from the mode that is enabled for the mount point. The writeback mode is not enabled unless the file system is mounted in writeback mode. If a file or directory is set to writeback mode, but the file system is mounted in another mode, the file or directory inherits the caching mode of the mount point.
To display information about a cache area
# sfcache list
NAME TYPE SIZE ASSOC-TYPE STATE DEVICE sfcachearea_1 VxVM 9.91g AUTO ONLINE ssd0_2809 sfcachearea_2 VxFS 31.97g AUTO ONLINE ssd0_0
Example of a VxVM cache area:
# sfcache list sfcachearea_1 Cachearea: sfcachearea_1 Assoc Type: AUTO Type: VxVM Size: 30.00g Cacheline Size: 64.00k Memory Size: 16.00m State: ONLINE Layout: CONCAT Number of Columns: 0 ASSOCIATED DATA OBJECTS: ASSOC DATAOBJECT NAME CACHING-MODE STATE KSTATE testdg/testvol1 read ENABLED ENABLED testdg/testvol2 read ENABLED ENABLED
Example of a VxFS cache area:
# sfcache list sfcachearea_2 Cachearea: sfcachearea_2 Assoc Type: AUTO Type: VxFS Size: 31.97g State: ONLINE Layout: - Number of Columns: 0 /dev/vx/dsk/sfcache_defaultdg/sfcachearea_2: FSUUID SIZE MODE MOUNTPOINT 3671ff51-9696-0000-872c-000056bcb408 4 KB read /mnt1