Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

Disabling I/O statistics collection
By default, Veritas Volume Manager collects I/O statistics on all objects in the
configuration. This helps you tune different parameters that depend upon the
environment and workload.
See “Tunable parameters for VxVM” on page 496.
See “DMP tunable parameters” on page 504.
After the tuning is done, you may choose to disable I/O statistics collection because
it improves I/O throughput.
To display whether I/O statistics are enabled
◆
Enter the following command:
# vxtune vol_stats_enable
If the system displays 1, I/O statistics collection is enabled. If it displays 0,
I/O statistics collection is disabled.
To disable I/O statistics collection until the next system reboot
◆
Enter the following command:
# vxtune vol_stats_enable 0
If you are concerned about high I/O throughput, you may also choose to disable
DMP I/O statistics collection.
To disable DMP I/O statistics collection
◆
Enter the following command:
# vxdmpadm iostat stop
Enabling I/O statistics collection
By default, Veritas Volume Manager collects I/O statistics on all objects in the
configuration. You only need to perform the tasks in this section if you disabled
I/O statistics collection.
To display whether I/O statistics are enabled
◆
Enter the following command:
# vxtune vol_stats_enable
If the system displays 1, I/O statistics collection is enabled. If it displays 0,
I/O statistics collection is disabled.
511Performance monitoring and tuning
Tuning VxVM