Physical Disk (NT_PHYSICAL_DISKS)
Attributes (parameters)
The following attributes are available for this monitor type:
Name | Description | Unit | Default Performance Key Indicator (KPI) |
---|---|---|---|
Average disk sec per read (PDpdAvgDiskSecPerRead) | Displays the average time, in seconds, for a read operation from the disk. | sec/read | No |
Average disk sec per transfer (PDpdAvgDiskSecPerTransfer) | Displays the average time, in seconds, at which data is transferred to or from the disk. | sec/transfer | No |
Average disk sec per write (PDpdAvgDiskSecPerWrite) | Displays the average time, in seconds, for a write operation to the disk. | sec/write | No |
The rate bytes are transferred to or from the disk (PDpdDiskBytesPerSec) | Displays the rate at which bytes are transferred to or from the disk during read or write operations. | MB/sec | No |
Disk queue length (PDpdDiskQueueLength) | Displays the number of requests outstanding on the disk at the time the performance data is collected. Recommendations If this parameter consistently has a value greater than 2, you should consider replacing the disk drive and/or the disk controller with faster versions.
Thresholds for alarms and warnings No default thresholds have been set for this parameter. | Number Of Requests | No |
Busy disk time (PDpdDiskTimePercent) | Displays the percentages of elapsed time that the disk spends servicing read or write requests. Recommendations If PDpdDiskTimePercent > 60% or PdpdDiskQueueLength > 2, then physical disk congestion is adversely affecting your system's performance. To remedy the situation, consider one or more of the following actions:
Determine if a memory shortage is impacting disk performance, To determine if a memory shortage is impacting disk performance, you can determine the portion of the disk I/O used for paging by the following formula: % disk time used for paging = 100 * (MEMmemPagesPerSec * 'PhysicalDisk Avg,DiskSec/Transfer')
If this value is > 10% of the total disk activity, then paging can be considered excessive. If this value is < 10% of the total disk activity, consider adding more physical memory and increasing the paging file size. | % | Yes |