Storage data caching concept
You can cache the storage data dynamically (start or stop caching) while the workload is running. The workload need not be brought down to an inactive state to perform the caching operation.
The following terms are used to explain the caching concept:
- Cache device
- A cache device is a solid-state drive (SSD) or a flash disk that is used for caching.
- Cache pool
- A cache pool is a group of cache devices that is used only for storage caching.
- Cache partition
- A cache partition is a logical cache device that is created from the cache pool.
- Target device
- A target device is a storage device that is being cached.
A single cache partition can be used to cache one or more target devices. When a target device is cached, all the read requests for the device blocks are routed to the caching software. If a specific block is found in the cache, the I/O request is processed from the cache device. If the requested block is not found in the cache, or if it is a write request, the I/O request returns to the target device.