This metric shows the sum of I/O throughput for all disks within the disk group. This gives an indication of the disk group I/O performance in terms of reads and writes for the instance.
The rest of the information in this section is only valid for this metric when it appears in either the Enterprise Manager Grid Control or the Enterprise Manager Database Control (if applicable).
The following table shows how often the metric's value is collected.
Target Version |
Collection Frequency |
All Versions |
Every 15 Minutes |
It is calculated using the Instance Disk Performance metric which in turn collects data from the GV$ASM_DISKGROUP and GV$ASM_DISK views for 10g Release 1 and the GV$ASM_DISKGROUP_STAT and GV$ASM_DISK_STAT views for 10g Release 2.
To calculate the average throughput of each disk, the total number of bytes read and written is divided by the total I/O time during the collection interval. This data is aggregated by the disk group name to get the average I/O throughput of a disk group.
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Related Topics
About Alerts
About the Metric Detail Page
Editing Thresholds
Understanding Line Charts
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