Compaq Infortrend manual Limitations, Database and Transaction-based Applications

Limitations:

There are limitations on the use of optimization modes.

1.You can select the stripe size of each array (logical drive) during the initial configuration. However, changing stripe size is only recommended for experienced engineers who have tested the effects tuning stripe sizes for different applications.

2.The array stripe size can only be changed during the initial configuration process.

3.Once the controller optimization mode is applied, access to different logical drives in a RAID system will follow the same optimized pattern. You can change the optimization mode later without having to re-organize your array.

Database and Transaction-based Applications:

This kind of applications usually include SQL server, Oracle server, Informix, or other data base services. These applications keep the size of each transaction down to the minimum, so that I/Os can be rapidly processed. Due to its transaction-based nature, these applications do not read or write a bunch of data in a sequential order. Access to data occurs randomly. The transaction size usually ranges from 2K to 4K. Transaction performance is measured in “I/Os per second” or “IOPS.”

Video Recording/Playback and Imaging Applications:

This kind of applications usually includes video playback, video post-production editing, or other applications of the similar nature. These applications have the tendency to read or write large files from and into storage in a sequential order. The size of each I/O can be 128K, 256K, 512K, or up to 1MB. The efficiency of these applications is measured in “MB/Sec.”

When an array works with applications such as video or image oriented applications, the application reads/writes from the drive as large-block, sequential threads instead of small and randomly accessed files.

The controller optimization modes have read-ahead buffer and other R/W characteristics tuned to obtain the best performance for these two major application categories.

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