HP XP7 Storage - Manual (Page 44)

4 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.
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“Performance of high-priority hosts” (page 44)
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“Upper-limit control” (page 44)
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“Threshold control” (page 45)
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“About I/O rates and transfer rates (traffic)” (page 45)
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 44)
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.
44 Performance Control operations