Infortrend
7-2
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:
T
his 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.
