Cautions And Restrictions For Performance Control - HPE XP7 User Manual

Table 23 Relationship between the thresholds of prioritized WWNs and the upper limits
of non-prioritized WWNs
Threshold settings
Threshold is set to the
prioritized WWN
Threshold is not set
to the prioritized
WWN

Cautions and restrictions for Performance Control

Real-time monitoring mode
Performance Control cannot be started when Performance Monitor is in real-time mode.
Before starting Performance Control, ensure that Time Range in the Monitor Performance
window is not set to Use Real Time.
Remote copy ports
When the remote copy functions (Continuous Access Synchronous, Continuous Access
Synchronous MF, Continuous Access Journal, Continuous Access Journal MF) or High
Availability are used in your environment, Performance Control monitors write I/O requests
issued from the initiator ports of your storage system.
If you set the priority attribute to an RCU target port, all I/Os received on the port are controlled
as the threshold control, and its performance data is added to the total number of I/Os (or
the transfer rate) of all prioritized ports. I/Os on the port will not be limited.
If you set the non-priority attribute to an RCU target port, I/O requests from the initiator port
are not controlled by threshold control, and I/Os on the port will not be limited. On the other
hand, I/O requests from a host are controlled by upper limit control, and I/Os on the port will
be limited.
Statistics for initiator/external ports
The initiator ports and external ports of your storage system are not controlled by Performance
Control. Although you can set Prioritize or Non-Prioritize to initiator ports and external ports
by using Performance Control, the initiator ports and the external ports become the prioritized
ports that are not under threshold control, regardless of whether the setting of the ports are
Prioritize or Non-Prioritize. If the port attributes are changed from Initiator/External into
Target/RCU Target, the settings by Performance Control take effect instantly and the ports
are subject to threshold or upper limit control.
The statistics of the Monitor Performance window are sum total of statistics on Target/RCU
Target ports that are controlled by Performance Control. The statistics does not include the
statistics of Initiator/External ports. Because the statistics of Initiator/External ports and
Target/RCU Target ports are based on different calculation methods, it is impossible to sum
up the statistics of Initiator/External ports and Target/RCU Target ports.
Settings on the Performance Control main window
The Performance Control main window has two tabs: the Port tab and the WWN tab. The
settings on only one tab at a time can be applied to the storage system. If you make settings
Upper limit is set (non-zero) to the non-prioritized
WWN
When thresholds are set to prioritized WWNs,
depending on the I/O rate or the transfer rate, the
following controls are executed.
If the total value of I/O rate or transfer rate exceeds
the threshold in all prioritized WWNs, upper limits
of all non-prioritized WWNs are in effect.
If the total value of I/O rate or transfer rate goes
below the threshold in all prioritized WWNs, upper
limits of all non-prioritized WWNs are not in effect.
The specified upper limit is always in effect.
Upper limit of the non-prioritized
WWN = 0
The threshold control of the
prioritized WWN is not executed.
Cautions and restrictions for Performance Control 113