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

Tunable parameters for VxVM
Table 15-1 lists the kernel tunable parameters for VxVM.
Table 15-1
Kernel tunable parameters for VxVM
DescriptionParameter
The interval at which utilities performing recoveries
or resynchronization operations load the current offset
into the kernel as a checkpoint. A system failure during
such operations does not require a full recovery, but
can continue from the last reached checkpoint.
The default value is 10240 sectors (10MB).
Increasing this size reduces the overhead of
checkpoints on recovery operations at the expense of
additional recovery following a system failure during
a recovery.
vol_checkpt_default
The count in clock ticks for which utilities pause if they
have been directed to reduce the frequency of issuing
I/O requests, but have not been given a specific delay
time. This tunable is used by utilities performing
operations such as resynchronizing mirrors or
rebuilding RAID-5 columns.
The default value is 50 ticks.
Increasing this value results in slower recovery
operations and consequently lower system impact
while recoveries are being performed.
vol_default_iodelay
Performance monitoring and tuning
Tuning VxVM
496