Technical data
Setting System Time
6.9 Using SYSMAN to Manage System Time
2. The next example sets the environment to NODE21, NODE22, and NODE23,
sets privilege, and modifies the system time on all three nodes:
SYSMAN> SET ENVIRONMENT/NODE=(NODE21,NODE22,NODE23)
SYSMAN> SET PROFILE/PRIVILEGE=LOG_IO
SYSMAN> CONFIGURATION SET TIME 12:38:00
3. The following example sets the environment to cluster and displays the
system time for all nodes:
SYSMAN> SET ENVIRONMENT/CLUSTER/NODE=NODE23
SYSMAN> CONFIGURATION SHOW TIME
System time on node NODE21: 19-APR-2001 13:32:19.45
System time on node NODE22: 19-APR-2001 13:32:27.79
System time on node NODE23: 19-APR-2001 13:32:58.66
6.9.1.1 Resetting System Time After January 1
The Time of Day Register (TODR), which the system uses to maintain system
time, has a limit of approximately 15 months. Between January 1 and April 1,
reset the system time; otherwise, the following problems might occur:
• The first time in a new year that you reboot an OpenVMS Cluster system or
a node in the system, one or more nodes display any of the following system
times:
A year in the past
A year in the future, which might cause passwords to expire and other
difficulties
A correct time, but a SHOW SYSTEM command indicates that the system
has been up since a time in the 1800s
• Even if you correct the system time during system boot, the following
problems might remain:
A SHOW SYSTEM command displays an incorrect up time such as a date
in the 1800s
The error log report (ERRLOG) shows errors for a year in the future
Batch jobs are waiting for a year in the future
Files have a creation or modification date in the future
Because the TODR has an approximate limit of 15 months, the system maintains
time by combining the TODR value with a base time recorded in the base system
image (SYS$LOADABLE_IMAGES:SYS.EXE). The definition of base time is:
01-JAN-CURRENT_YEAR 00:00:00.00
Because all TODRs ordinarily have the same base, multiple CPUs can boot off
the same system disk, and you can use multiple system disks on one CPU; the
system sets the time correctly.
When a SET TIME command is issued (with or without specifying a time),
OpenVMS performs the following actions:
1. Writes the current time to the system image file
2. Resets the TODR as an offset within the current year
Setting System Time 6–25