QUERY CLOUDREADCACHE (Query a cloud read cache)

Use this command to display statistics about the cloud read cache of one or more cloud-container storage pools. The cloud read cache has disk storage space that is used in the storage pool's directories as a staging area for restoring data. When data is downloaded in bulk to the cloud read cache, read requests are redirected to the storage pool's disk storage location to help improve the performance of restore operations.

This command is valid for cloud-container storage pools that are enabled with the CLOUDREADCACHE parameter. You can use this command to measure the effectiveness of the cloud read cache.

Privilege class

Any administrator can issue this command.

Syntax

Parameters

pool_name: Specifies the name of the cloud-container storage pool for which you want to query cloud cache information. This parameter is optional. You can use a wildcard character to specify this name. If you do not specify a pool name, information about all cloud read caches for all cloud-container storage pools is displayed.

Example: Display cloud cache information

Display cloud cache information about a cloud-container storage pool that is named CLOUDCONT.

query cloudreadcache cloudcont

                      Storage Pool Name: CLOUDCONT
                       Cloud Read Cache: On
             Read Cache Directory Count: 1
     Read Cache Quarantined Directories: 0
                    Total Read Requests: 254,879
              Total Cache Read Requests: 252,930
                Total Read Request Data: 50.0 G
          Total Cache Read Request Data: 49.7 G
              Total Container Downloads: 63
         Successful Container Downloads: 63
             Failed Container Downloads: 0
            Current Container Downloads: 63
          Total Container Download Data: 50.1 G
        Current Container Download Data: 50.1 G
        Maximum Container Download Data: 50.1 G
Today's Maximum Container Download Data: 50.1 G

In this example, the statistics are collected from an instance of a cloud read cache for a cloud-container storage pool. When you disable and enable the CLOUDREADCACHE parameter for a storage pool, cloud read cache statistics are reset. If you query the cloud read cache again, you will obtain statistics for a newly created instance of the cloud read cache.

Field descriptions

Storage Pool Name: The name of the storage pool for which the cloud cache information is displayed.
Cloud Read Cache: The value of the CLOUDREADCACHE parameter for the storage pool.
Read Cache Directory Count: The number of directories that are assigned to the storage pool.
Read Cache Quarantined Directories: The number of storage pool directories that are quarantined because download operations to those directories previously failed. The directories in this count are currently not used for restore operations.
Total Read Requests: The total number of read requests that were issued to the storage pool since the cloud read cache was created.
Total Cache Read Requests: The total number of read requests issued to the storage pool that were satisfied by the cloud read cache.
Total Read Request Data: The total amount of read data that was requested from the storage pool since the cloud read cache was created.
Total Cache Read Request Data: The total amount of read data that is satisfied by the cloud read cache.
Total Container Downloads: The total number of cloud containers that were downloaded.
Successful Container Downloads: The total number of cloud containers that were downloaded to the cloud read cache.
Failed Container Downloads: The total number of cloud containers that failed to be downloaded to the cloud read cache.
Current Container Downloads: The total number of cloud containers that are currently downloaded to the cloud read cache.
Total Container Download Data: The total amount of cloud container data that is downloaded to the cloud read cache.
Current Container Download Data: The current amount of cloud container data that is downloaded to the cloud read cache.
Maximum Container Download Data: The maximum amount of cloud container data that existed at a time in the cloud read cache.
Today's Maximum Container Download Data: The maximum amount of cloud container data that existed in the cloud read cache today.

Related commands

Table 1. Commands related to QUERY CLOUDREADCACHE
Command	Description
QUERY CONTAINER (Query a container)	Displays information about a container.
QUERY STGPOOL (Query storage pools)	Displays information about storage pools.
QUERY STGPOOLDIRECTORY (Query a storage pool directory)	Displays information about storage pool directories.
UPDATE STGPOOL (Update a cloud-container storage pool)	Update a cloud-container storage pool.