Technical data

System Management Features

4.12 New System Parameters

This section contains deﬁnitions of system parameters that are new in OpenVMS

Version 7.3.

4.12.1 AUTO_DLIGHT_SAV

AUTO_DLIGHT_SAV is set to either 1 or 0. The default is 0.

If AUTO_DLIGHT_SAV is set to 1, OpenVMS automatically makes the change to

and from daylight saving time.

4.12.2 FAST_PATH_PORTS

FAST_PATH_PORTS is a static parameter that deactivates Fast Path for speciﬁc

drivers.

FAST_PATH_PORTS is a 32-bit mask. If the value of a bit in the mask is 1, Fast

Path is disabled for the driver corresponding to that bit. A value of -1 speciﬁes

that Fast Path is disabled for all drivers that the FAST_PATH_PORTS parameter

controls.

Bit position zero controls Fast Path for PKQDRIVER (for parallel SCSI), and bit

position one controls Fast Path for FGEDRIVER (for Fibre Channel). Currently,

the default setting for FAST_PATH_PORTS is 0, which means that Fast Path is

enabled for both PKQDRIVER and FGEDRIVER.

In addition, note the following:

• CI drivers are not controlled by FAST_PATH_PORTS. Fast Path for CI is

enabled and disabled exclusively by the FAST_PATH system parameter.

• FAST_PATH_PORTS is relevant only if the FAST_PATH system parameter

is enabled (equal to 1). Setting FAST_PATH to zero has the same effect as

setting FAST_PATH_PORTS to -1.

For additional information, see FAST_PATH and IO_PREFER_CPUS.

4.12.3 GLX_SHM_REG

On Galaxy systems, GLX_SHM_REG is the number of shared memory region

structures conﬁgured into the Galaxy Management Database (GMDB). If you

set GLX_SHM_REG to 0, the default number of shared memory regions are

conﬁgured.

4.12.4 LCKMGR_CPUID (Alpha)

The LCKMGR_CPUID parameter controls the CPU that the Dedicated CPU Lock

Manager runs on. This is the CPU that the LCKMGR_SERVER process will

utilize if you turn this feature on with the LCKMGR_MODE system parameter.

If the speciﬁed CPU ID is either the primary CPU or a nonexistent CPU, the

LCKMGR_SERVER process will utilize the lowest nonprimary CPU.

LCKMGR_CPUID is a DYNAMIC parameter.

For more information, refer to the LCKMGR_MODE system parameter.

System Management Features 4–15