InfoScale™ 9.0 SmartIO for Solid-State Drives Solutions Guide - Solaris
- Introducing SFHA Solutions SmartIO
- Using the SmartIO feature: use cases
- About SmartIO read caching for applications running on VxVM volumes
- About SmartIO read caching for applications running on VxFS file systems
- About SmartIO caching on SSD devices exported by FSS
- About SmartIO write-back caching for applications running on VxFS file systems
- About multiple SmartIO cache areas for read and write-back caching on VxFS file systems
- About SmartIO caching for Oracle databases on VxFS file systems
- Prerequisites and configuration for using the SmartIO plug-in for Oracle
- Setting default SmartIO caching policies for a database running on a VxFS file system
- Setting SmartIO caching policies for database objects
- Pinning and unpinning database objects
- Enabling and disabling caching for the database
- Listing cache policy details for the database
- Listing cache statistics for the database
- About SmartIO caching for databases on VxVM volumes
- Administering SmartIO
- Creating a cache area
- Displaying information about a cache area
- Enabling or disabling caching for a data object
- Adding a device to the cache area
- Pausing caching from a volume to a cache area
- Removing a device from the cache area
- Destroying a cache area
- Setting the attributes of the VxVM cache area
- Setting or changing the caching mode for a VxFS cache area
- Flushing dirty data from a writeback cache area
- Tuning the writeback caching
- Viewing the SmartIO cache statistics
- Troubleshooting and error handling
- Appendix A. Command reference
Customizing the caching behavior
By default, SmartIO caches the file data based on the workload. SmartIO loads portions of files into the cache based on I/O access. When the cache area fills, data may be evicted to make room for caching new data. SmartIO uses criteria such as frequency of access to evict data. While the data is in the cache, the subsequent I/Os to that file data are satisfied from the cache. If the data is evicted, any subsequent I/O request is served from the primary storage. SmartIO may then cache the data again.
To maximize the use of the cache, you can customize the caching behavior to control when files are loaded or evicted from the cache. You can customize the caching behavior, using the following operations:
The load operation preloads files into the cache before the I/O accesses the files. The files are already in the cache so that the I/Os return more quickly. By default, the files are loaded in the background. Use the -o sync operation to load the files synchronously, which specifies that the command does not return until all the files are loaded. The files that are loaded in this way are subject to the usual eviction criteria.
The pin operation prevents the files from being evicted from the cache. You can pin commonly used files so that SmartIO does not evict the files and later need to cache the files again. A pinned file is kept in the cache indefinitely, until it is deleted or explicitly unpinned. If you pin a file with the -o load option, the operation also caches the file contents synchronously. If you do not specify the -o load option, the file contents are cached based on I/O access.
The unpin operation removes files from the pinned state. The unpin operation does not cause the file to be immediately evicted. SmartIO considers the file for eviction in the same way as any other file, when space is required in the cache.
For each of these operations, you can specify files individually, or specify a directory name to affect all of the files in a directory. Use the -r option to make the selection recursive.
To load files or directories
- To load files or directories to the cache, specify one or more file names or directory names to the following command.
# sfcache load [-r] [-o sync] {file|dir}[file2|dir2...]Use the -r option to make the selection recursive.
Use the -o sync option to specify that the command does not return until all the files are loaded.
To pin files or directories
- To pin files or directories to the cache, specify one or more file names or directory names to the following command.
# sfcache pin [-o load] [-r] {file|dir}[file2|dir2...]Use the -r option to make the selection recursive.
Use the -o load option to load the file synchronously into the cache.
To unpin files or directories
- To unpin files or directories from the cache, specify one or more file names or directory names to the following command.
# sfcache unpin [-r] {file|dir} [file2|dir2...]Use the -r option to make the selection recursive.