Technical data

System Management Features

4.1 OpenVMS Support for New AlphaServer GS Series Systems

4.1.3 OpenVMS Support for CPU Online Replace

With OpenVMS Alpha Version 7.3, you can replace secondary CPUs on a running

system without rebooting, which provides increased system maintainability and

serviceability. This feature is supported only on AlphaServer GS160/320 systems.

Note that replacing the primary CPU requires rebooting.

To use this feature, you must ﬁrst download console ﬁrmware Version 5.9B from

the following location:

http://ftp.digital.com/pub/DEC/Alpha/firmware/

After you upgrade the console with the latest ﬁrmware, you can then use the

following DCL commands to replace a CPU without rebooting:

1. Direct OpenVMS to stop scheduling processes on the CPU:

$ STOP/CPU n

(n is the number of the CPU to be stopped.)

2. Power off the running CPU:

$ SET CPU/POWER=OFF n

3. When the light on the CPU module has turned from green to amber,

physically remove the CPU module from the system. Then put in a new

CPU.

4. Power on the CPU:

$ SET CPU/POWER=ON n

OpenVMS automatically adds the CPU to the active set of processors.

Note that the Galaxy Conﬁguration Utility (GCU) also supports this capability.

4.2 Automatic Setting of Daylight Savings Time

System parameter AUTO_DLIGHT_SAV controls whether OpenVMS will

automatically change system time to and from Daylight Savings Time when

appropriate. A value of 1 tells OpenVMS to automatically make the change. The

default is 0 (off). This is a static parameter.

However, if you have a time service (such as DTSS), that time service continues to

control time changes, and OpenVMS does not interfere. Do not enable automatic

daylight savings time if you have another time service.

For more information, refer to the OpenVMS System Manager’s Manual.

4.3 Class Scheduler for CPU Scheduling

With OpenVMS Version 7.3, there is a new SYSMAN-based interface for class

scheduling. This new class scheduler, implemented on both VAX and Alpha

systems, gives you the ability to designate the amount of CPU time that a

system’s users may receive by placing the users into scheduling classes. Each

class is assigned a percentage of the overall system’s CPU time. As the system

runs, the combined set of users in a class are limited to the percentage of CPU

execution time allocated to their class. The users may get some additional CPU

time if /windfall is enabled for their scheduling class. Enabling the /windfall

allows the system to give a small amount of CPU time to a scheduling class when

a CPU is idle and the scheduling class’ allotted time has been depleted.

4–2 System Management Features