Diskperf; Disk Performance Monitor Objects And Their Meaning - Compaq 117755-003 - ProSignia - 740 Configuration Manual

Page 14 Configuration and Tuning of Sybase System 11 for Microsoft Windows NT on Compaq Servers
transaction rate, Sybase SQL Server would perform the checkpoint approximately every 2
minutes. Also if trunc. log on checkpoint is set then a checkpoint will occur every minute
Refer to the Disk Subsystem Planning section for more detailed information on how
checkpointing can effect disk throughput.

Diskperf

The diskperf option
monitoring performance of the drive subsystem. If this option is disabled, performance monitor
will not be able to monitor low level disk-related activity, such as LogicalDisk and PhysicalDisk
counters.
Having this option enabled slightly degrades performance. Enable diskperf only when needed,
then disable it to get maximum performance.
You can enable or disable diskperf using Control Panel/Devices or by issuing the diskperf -y|n
command from the system prompt. When using the Control Panel, set diskperf to automatically
start at boot time to enable. You must restart your system for the diskperf option to become
effective.

Disk Performance Monitor Objects and Their Meaning

You can monitor LogicalDisk- and PhysicalDisk-related objects, such as Avg. Disk sec/Transfer
or Disk Transfers/sec. Monitoring LogicalDisk and PhysicalDisk-related objects requires you to
have the diskperf option enabled, which slightly reduces performance.
Note that resetting the diskperf option requires you to reboot your machine.
Object: Logical Disk
Counter: Avg. Disk sec/Read, Avg. Disk sec/Write
The Avg. Disk sec/Read and Avg. Disk sec/Write counters monitor the average number of
seconds for read or write operations from or to a disk, respectively.
Use the following guidelines when optimizing the disk subsystem. Do not have more average
disk seconds per read or write operation than the values in the table below.
Transaction Log Access (with the Array
Accelerator enabled)
Database Access (with the Array
Accelerator enabled)
If your values are much higher than those suggested in the above table, you may want to increase
the speed of your disk subsystem by adding more drives or using faster drives.
Object: Logical Disk
Counter: Disk Transfers/sec
The Disk Transfers/sec counter monitors the rate of read and write operations on the disk. It is
important to realize that if you have a Compaq SMART or SMART-2 SCSI Array controller and
several drives allocated to a logical volume, this counter monitors the total number of disk
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The diskperf option is described in a greater detail in the Microsoft Windows NT Resource Kit.
1996 Compaq Computer Corporation, All Rights Reserved
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allows you to monitor the disk subsystem activity. It is very useful when
Avg. Disk sec/Read
n/a
20-40msec
Avg. Disk sec/Write
<=10msec
<=10msec
Doc No 143A/0596