Pool usage thresholds

Dynamic Provisioning monitors pool capacity using thresholds. A threshold is the proportion (%) of used pool capacity to the total pool capacity, or the used capacity of the parity group that is related to the used pool capacity. Each pool has its own pool threshold values.

• Warning Threshold: Set the value between 1% and 100%, in 1% increments. The default is 70%.

• Depletion Threshold: Set the value between 1% and 100%, in 1% increments. The default is 80%.

Pool usage over either threshold causes a warning to be issued through SIMs (Service Information Messages) to Device Manager - Storage Navigator and SNMP (Simple Network Management Protocol) traps to the open-systems host. For more information on SNMP traps and the SNMP Manager, see the SNMP Agent User Guide . See Working with SIMs for more information about SIMs.

The following figure shows a pool capacity of 1,000 GB, Warning Threshold of 50%, and Depletion Threshold of 80%. If the used pool capacity is larger than 50% (500 GB) of the total pool capacity, a SIM and an SNMP trap are reported. If the used pool capacity increases and exceeds the Depletion Threshold (80%), a SIM and an SNMP trap are reported.

In this scenario, if the actual pool usage percentage is 50.1%, only 50% appears on the Device Manager - Storage Navigator window because the capacity amount is truncated after the decimal point. If the threshold is set to 50%, a SIM and an SNMP trap are reported even though the pool usage percentage appearing on the screen does not indicate an exceeded threshold.