Pool utilization thresholds
Dynamic Provisioning monitors pool capacity using thresholds. A threshold is the proportion (%) of used capacity of the pool to the total 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 will cause a warning to be issued in the form of SIMs (Service Information Messages) to Hitachi 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 Hitachi SNMP Agent User Guide. See Working with SIMs for more information about SIMs.
The following figure illustrates a total pool capacity of 1 TB, Warning Threshold of 50%, and Depletion Threshold of 80%. If the used capacity of the pool is larger than 50% (500 GB) of the total pool capacity, a SIM and an SNMP trap are reported. If the used capacity of the pool increases and exceeds the Depletion Threshold (80%), a SIM and an SNMP trap are reported again.
Note that in this scenario, if the actual pool usage percentage is 50.1%, only 50% appears on the Hitachi 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.