Performance Control Operations; Overview Of Performance Control; Performance Of High-Priority Hosts; Upper-Limit Control - HPE XP7 User Manual

5 Performance Control operations

This chapter describes and provides instructions for managing host I/O activity using Performance
Control.

Overview of Performance Control

Performance Control allows you to set upper limits of the number of accesses from the server
to storage system as well as the amount of data transfer. The upper limits are automatically
disabled when the traffic between the server and storage system drops to user-defined levels.
Using Performance Control you can designate prioritized ports (for example, for production
servers) and non-prioritized ports (for example, for development servers) and set upper limits
and thresholds for the I/O activity of these ports to prioritize I/O operations to host servers requiring
high-throughput I/O operations and prevent low-priority activities from negatively impacting
high-priority activities. Performance Control operations can be performed only for ports connected
to open-systems hosts.
"Performance of high-priority hosts" (page 105)
"Upper-limit control" (page 105)
"Threshold control" (page 106)
"About I/O rates and transfer rates (traffic)" (page 106)

Performance of high-priority hosts

In a SAN environment, the storage system is usually connected with many host servers. Some
types of host servers often require higher performance than others. For example, production
servers such as database and application servers that are used to perform daily tasks of business
organizations usually require high performance. If production servers experience decreased
performance, productivity in business activities can be negatively impacted. To prevent this from
happening, the system administrator needs to maintain the performance of production servers
at a relatively high level.
Computer systems in business organizations often include development servers, which are used
for developing, testing, and debugging business applications, as well as production servers. If
development servers experience decreased performance, development activities can be negatively
impacted, but a drop in development server performance does not have as much negative impact
to the entire organization as a drop in production server performance. In this case, you can use
Performance Control to give higher priority to I/O activity from production servers than I/O activity
from development servers to manage and control the impact of development activities.
Related topics
"Overview of Performance Control" (page 105)

Upper-limit control

Using Performance Control you can limit the number of I/O requests from servers to the storage
system as well as the amount of data that can be transferred between the servers and the storage
system to maintain production server performance at the required levels. This practice of limiting
the performance of low-priority host servers is called upper-limit control. The upper-limit control
is automatically disabled when traffic between the servers and the storage system drops to
user-defined levels called thresholds.
Overview of Performance Control 105