Busy Disk Time (PDpdDiskTimePercent)
Displays the percentages of elapsed time that the disk spends servicing read or write requests.
Good disk performance enhances virtual memory performance and reduces the elapsed time required to load programs that perform a large number of I/O requests.
Disk performance may be impacted by a shortage of physical memory.
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:
- Install a faster disk and controller.
- Distribute the workload as evenly as possible among different disk drives.
- Use the NTFS file system. NTFS is more efficient for large disks (400 MB or more).
- Create mirrored data sets.
- Create striped data sets.
- Disable short name generation on the NTFS file system.
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')
- MEMmemPagesPerSec is the number of hard page faults.
- PhysicalDisk Avg,DiskSec/Transfer is the time in seconds of the average disk transfer. You can add this parameter to PATROL using the PATROL Performance Monitor Wizard. You can also find this value using Windows's Performance Monitor.
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.
Thresholds for alarms and warnings
Item | Default Threshold | State |
Border | 0-100 | alarm outside of border |
Alarm 1 | 90-95 percent | warning |
Alarm 2 | 95-100 percent | alarm |
Consider adjusting these values to suit the needs of your system. Read the baselining overview for information on how to determine what is normal for your system.
Default properties
Property | Default value |
|---|---|
BMC PATROL properties | |
Application class | NT_PHYSICAL_DISKS |
Command type | not applicable |
Icon style | graph |
Unit | percentage |
Border range | undefined |
Alarm1 range | undefined |
Alarm2 range | undefined |
Scheduling (poll time) | inherits poll time of collector |
Active at installation | yes |
Parameter type | consumer |
Value set by | PDPhysicalDiskColl |
BMC ProactiveNet Performance Management properties | |
Monitor type | Physical Disk |
Key Performance Indicator | Yes |
Monitor for abnormalities | Yes |
Graph by default | Yes |
Availability | No |
Response time | No |
Normal distribution | Yes |
Statistical | Yes |