Veritas Volume Manager 5.0.1 Administrator's Guide, HP-UX 11i v3, First Edition, November 2009

Table 16-2
DMP parameters that are tunable (continued)
DescriptionParameter
If DMP statistics gathering is enabled, set this tunable to
on (default) to have the DMP path restoration thread probe
idle LUNs. Set this tunable to off to turn off this feature.
(Idle LUNs are VM disks on which no I/O requests are
scheduled.) The value of this tunable is only interpreted
when DMP statistics gathering is enabled. Turning off
statistics gathering also disables idle LUN probing.
The default value is on.
dmp_probe_idle_lun
The maximum number of queued I/O requests on a path
during I/O throttling.
The default value is 40.
A value can also be set for paths to individual arrays by
using the vxdmpadm command.
See “Configuring the I/O throttling mechanism” on page 186.
dmp_queue_depth
The interval attribute specifies how often the path
restoration thread examines the paths. Specify the time in
seconds.
The default value is 300.
The value of this tunable can also be set using the vxdmpadm
start restore command.
See “Configuring DMP path restoration policies” on page 189.
dmp_restore_interval
If the DMP restore policy is check_periodic, the number
of cycles after which the check_all policy is called.
The default value is 10.
The value of this tunable can also be set using the vxdmpadm
start restore command.
See “Configuring DMP path restoration policies” on page 189.
dmp_restore_cycles
Performance monitoring and tuning
Tuning VxVM
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