InfoScale™ 9.0 SmartIO for Solid-State Drives Solutions Guide - Solaris

Last Published:
Product(s): InfoScale & Storage Foundation (9.0)
Platform: Solaris
  1. Introducing SFHA Solutions SmartIO
    1.  
      About SmartIO for solid-state drives
    2.  
      About SmartIO in an SFHA environment
    3.  
      About SmartIO in an Active/Active cluster environment
    4. About SmartIO in the Solaris virtualized environments
      1.  
        Performing live migration between LDOMs in the SmartIO environment
    5.  
      About the SmartIO caching profiler tool
  2. Using the SmartIO feature: use cases
    1. About SmartIO read caching for applications running on VxVM volumes
      1.  
        Required configuration for SmartIO read caching for VxVM volumes
      2.  
        Automatic caching for VxVM volumes
      3.  
        Setting up SmartIO read caching for VxVM volumes
      4.  
        Verifying the VxVM cache area and monitoring the caching
    2. About SmartIO read caching for applications running on VxFS file systems
      1.  
        Required configuration for SmartIO read caching for a VxFS file system
      2.  
        Automatic caching for VxFS file systems
      3.  
        Setting up SmartIO read caching for VxFS file systems
      4.  
        Verifying the VxFS cache area and monitoring the caching
      5.  
        Customizing the caching behavior
    3. About SmartIO caching on SSD devices exported by FSS
      1.  
        Status of cache areas when nodes leave or join the cluster
      2.  
        Setting up cache areas using SSDs exported by FSS
    4. About SmartIO write-back caching for applications running on VxFS file systems
      1.  
        Required configuration for SmartIO write-back caching for a VxFS file system
      2.  
        Setting up SmartIO write-back caching for VxFS file systems
      3.  
        Verifying the VxFS cache area and monitoring the caching (writeback mode)
    5. About multiple SmartIO cache areas for read and write-back caching on VxFS file systems
      1.  
        About the smartiocache option
      2.  
        Converting VxFS cache areas from one type to another
      3.  
        Setting up multiple cache areas on a system
      4.  
        Verifying the VxFS cache areas
    6. About SmartIO caching for Oracle databases on VxFS file systems
      1.  
        Prerequisites and configuration for using the SmartIO plug-in for Oracle
      2.  
        Setting default SmartIO caching policies for a database running on a VxFS file system
      3.  
        Setting SmartIO caching policies for database objects
      4.  
        Pinning and unpinning database objects
      5.  
        Enabling and disabling caching for the database
      6.  
        Listing cache policy details for the database
      7.  
        Listing cache statistics for the database
    7. About SmartIO caching for databases on VxVM volumes
      1.  
        Applying a SmartIO database caching template for a VxVM volume
  3. Administering SmartIO
    1.  
      Creating a cache area
    2.  
      Displaying information about a cache area
    3. Enabling or disabling caching for a data object
      1.  
        Enabling or disabling caching for a file system
      2.  
        Enabling or disabling caching for a data volume
    4.  
      Adding a device to the cache area
    5.  
      Pausing caching from a volume to a cache area
    6.  
      Removing a device from the cache area
    7.  
      Destroying a cache area
    8.  
      Setting the attributes of the VxVM cache area
    9.  
      Setting or changing the caching mode for a VxFS cache area
    10.  
      Flushing dirty data from a writeback cache area
    11.  
      Tuning the writeback caching
    12. Viewing the SmartIO cache statistics
      1.  
        Viewing the detailed caching stats for a VxVM cache area
      2.  
        Viewing the detailed caching stats for a VxFS cache area
  4. Troubleshooting and error handling
    1. Support for a persistent or 'warm' VxVM cache
      1.  
        Primary volume failure with a stale cache could cause possible data corruption
      2.  
        Migrating a cache during HA failover is not supported
    2.  
      Cache area is lost after a disk failure (3158482)
    3.  
      Cache is not online after a reboot
    4.  
      Recovering the write-back cache after a node failure
  5. Appendix A. Command reference
    1.  
      SmartIO command reference

Recovering the write-back cache after a node failure

In writeback mode, SmartIO stores data in the cache before writing the data to the disk. If the device that contains the cached data fails, the unflushed data in the cache area must be flushed to the disk when the system comes back online. Until the cached data is flushed, the file data that is cached in writeback mode may not be completely present on the disk.

In some cases, the SmartIO cache containing dirty write-back data is not available for flushing. For example, an error may have occurred on the SSD device that contains the cache area. When the cache device comes back online, then dirty data for such files is skipped from flushing. The files that have pending dirty data are not accessible. Any I/O on those files (except deletion) returns an I/O error (EIO).

The following error message is displayed in the syslog:

Writeback cache recovery is failed for mounted_device with error 
error_code:

If you want to restore access to such files, use the following procedure.

Restoring access to files that are not accessible

  1. To restore access to the files, use the following command. This command requires root privileges.
    # sfcache restore-access -r {mount_point|directory|file}

    For example:

    # /usr/sbin/sfcache restore-access /testFS

    For cluster file systems, run the sfcache restore-access command on each node of the cluster.

  2. After you restore access to the files or directories, restore access for the mount point.
    # sfcache restore-access -r mount_point

    For example:

    # /usr/sbin/sfcache restore-access /testFS
  3. To enable the write-back caching for the file system, use the following commands:
    #  sfcache disable /testFS
# sfcache enable /testFS