Displaying information about a cache area

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

  1. Use the following command to display information about the cache areas on the system.
    # 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
  2. Use the following command to display information about a specific cache area.

    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