Monitoring Exadata Storage Cells - Oracle Exadata Recipes: A Problem-Solution Approach - page 364

learn cycle and may temporarily enter WriteThrough Caching mode as part of the learn cycle. Disk
write throughput might be temporarily lower during this time. The flash drives are not affected.
The battery learn cycle is a normal maintenance activity that occurs quarterly and runs for
approximately 1 to 12 hours. Note that many learn cycles do not require entering WriteThrough
caching mode. When the disk controller cache returns to the normal WriteBack caching mode, an
additional informational alert will be sent. Battery Serial Number : 467 Battery Type
: iBBU08 Battery Temperature : 40 C Full Charge Capacity : 1417 mAh Relative Charge
: 96 % Ambient Temperature : 27 C"
2_2 2012-10-17T10:22:13-04:00 clear "All disk drives are in WriteBack caching mode.
Battery Serial Number : 467 Battery Type : iBBU08 Battery Temperature : 45 C Full
Charge Capacity : 1408 mAh Relative Charge : 69 % Ambient Temperature : 27 C"
CellCLI>
You can see three distinct alerts with names 1 , 2_1 , and 2_2 . Alerts 2_1 and 2_2 are related to each other; 2_1
indicates an informational alert showing that the disk controller battery is undergoing a “learn cycle,” and Alert 2_2
indicates that the message is cleared after the completion of the cycle. Each alert object has multiple attributes. Use
the following list alerthistory command with the detail option to display each attribute of an alert:
CellCLI> list alerthistory 2_1 detail
name: 2_1
alertMessage: "The disk controller battery is executing a learn cycle and may
temporarily enter WriteThrough Caching mode as part of the learn cycle. Disk write throughput
might be temporarily lower during this time. The flash drives are not affected. The battery
learn cycle is a normal maintenance activity that occurs ... output omitted for brevity
alertSequenceID: 2
alertShortName: Hardware
alertType: Stateful
beginTime: 2012-10-17T05:00:33-04:00
endTime: 2012-10-17T10:22:13-04:00
examinedBy:
metricObjectName: LUN_LEARN_CYCLE_ALERT
notificationState: 0
sequenceBeginTime: 2012-10-17T05:00:33-04:00
severity: info
alertAction: Informational.
CellCLI>
Stateful and Stateless Alerts
In the above output, the alertType indicates that this is a Stateful alert, which means that it can, at a later date, be
tested to detect whether the alert condition or state has changed. Alert 2_2 is the partner of Alert 2_1 and, in this case,
at the completion of the operation, the alert will be cleared. Exadata also raises Stateless alerts. These alerts indicate
point-in-time events that do not reflect a persistent condition—they simply communicate that an event occurred.