Cache storage

The amount of storage space that you dedicate to cache storage varies greatly based on requirements such as the number of reports that you store on the system, the compression ratio that Content Manager OnDemand can achieve, and the amount of time that you need to store a report in cache storage.

Most customers store reports in cache storage for a short time to provide the fastest retrieval for the most frequently used reports. As reports age, and retrieval requests for them are much less frequent. The reports can be retrieved from archive media.

You might also keep records in cache storage when many users access them at the same time. Because the archive storage manager might require from six to sixty seconds to mount an optical or tape storage volume and retrieve a report, it is usually not possible to support a high transaction rate for reports stored on archive media.

Another use of cache storage is for reports that have a short life, such as one week or one month. You can store these types of reports in cache storage and the system can be configured to automatically delete them when they reach their expiration date. Cache storage can also be used to hold reports for which you do not need a backup copy.

Use the following calculation to determine the amount of disk space required for cache storage: Cache Storage = Size of Data per week * Number of Weeks to cache * Data Compression ratio * 1.1.

For example, if you plan to load 2 GB of report data on the system each week, the reports must be maintained in cache storage for 26 weeks, and the compression ratio is 8:1 (0.13), then the storage space required for cache storage space can be calculated as follows: Cache Storage = 2 GB * 26 * .13 * 1.1 = 7 436 000 000