The QoS alert function issues a SIM to notify to the user that the status of a QoS volume or a QoS group is out of the setting range. After you set the QoS alert function, the alert conditions are periodically checked in the storage system. The QoS alert function provides the upper-limit alert, lower-limit alert, and response delay alert functions.
- When the storage system is powered on or powered off, the following information is initialized:
- Management information used for outputting a SIM for alert notification once every 24 hours
- Latest time when an alert occurs
- If you change the threshold period for alert notification, an alert might be output even if the new threshold period is not reached, depending on when you changed the setting and the time at which the threshold period is judged.
- If the target response time is exceeded, the continuous time is counted. However, if the status with no I/O operations continues for one second or more, the continuous time count is reset.
Upper-limit alert: An upper-limit alert (SIM ee0000 for a volume or ee3000 for a QoS group) is output when the upper-limit value set for a QoS volume or a QoS group is continuously reached for the time period specified as the threshold period. Since I/O processing is suppressed when the throughput reaches the upper-limit value on the volume or the QoS group with the upper-limit control set, you can use this alert function to monitor whether and how often the I/O processing is suppressed.
The upper-limit alert function is disabled by default. You can set the threshold period for the upper-limit alert from 1 second to 600 seconds (10 minutes). The storage system outputs a SIM for alert notification once per 24 hours. If one volume or one QoS group reaches its upper limit more than once, or if a different volume also reaches its upper-limit within 24 hours, the second and subsequent alerts are not reported. The time when the upper-limit alert is output is recorded inside the storage system. If you want to display the time, use CCI. For more information, see the command example in Commands for QoS operations.
Lower-limit alert: A lower-limit alert (SIM ee1000) is output when the state in which the lower-limit value set for a QoS volume is not reached continues for the time period specified as the threshold period. You can use this alert function to monitor the status of lower-limit control of throughput.
The lower-limit alert function is disabled by default. You can set the threshold period for the lower-limit alert from 1 second to 600 seconds (10 minutes). The storage system outputs a SIM for alert notification once per 24 hours. If one volume does not reach its lower limit more than once, or if another volume also does not reach its lower limit within 24 hours, the second and subsequent alerts are not reported. The time when the lower-limit alert is output is recorded inside the storage system. If you want to display the time, use CCI. For more information, see the command example in Commands for QoS operations.
Response delay alert: A response delay alert (SIM ee2000 for a volume or ee5000 for a QoS group) is output when the state, in which the target response time corresponding to the priority set for a QoS volume or QoS group is exceeded, continues for the time period specified as the threshold period. You can use this alert function to monitor the status of delay for the target response time.
The response delay alert is disabled by default. You can set the threshold period for the response delay alert from 1 second to 600 seconds (10 minutes). The storage system outputs a SIM for alert notification once per 24 hours. If one volume or one QoS group exceeds the target response time more than once, or if another volume exceeds the target response time within 24 hours, the second and subsequent alerts are not reported. The time when the response delay alert is output is recorded inside the storage system. If you want to display the time, use CCI. For more information, see the command example in Commands for QoS operations.