============================================================================= Run Date: OCT 28, 2004 Designation: XU*8*367 Package : XU - KERNEL Priority: Mandatory Version : 8 SEQ #297 Status: Released Compliance Date: NOV 28, 2004 ============================================================================= Subject: Fallback Daylight Savings Time Adjustment for VistA Systems Category: - Informational Description: ============ Daylight Savings Time ends on Sunday, October 31. Clocks will fall-back one hour. This potentially affects some VistA applications that may have date/time sensitive data. This is not a new issue. This patch is provided as guidance to those sites who have expressed concern. It does not represent policy. During the fall-back time change process, it is recommended to either write-inhibit (on DSM systems) or shutdown (on Cache systems) the VistA database for 1 hour so that VistA time dependent data is not "over-written", lost, or otherwise corrupted. An example issue is data stored in an M global subscript in inverse internal data/time format. There is the potential to have new data overwrite existing data after turning back the clock. VistA sites should be aware of this issue and make plans, and take appropriate actions, as necessary (i.e., advance notification to users, take advantage of contingency plans during system down time, and make VistA unavailable for one hour during the "Fallback" time change on Sunday, October 31st). The following is provided as guidance to VistA sites. VistA Backup Considerations =========================== If a VistA database backup is scheduled to occur during the time change the following should be done prior to the time change: - Reschedule the backup to take place after the time change has completed. Cache/VMS Sites =============== Prior to Sunday, October 31 - Cache/VMS sites should verify that an automatic time change will occur on the VMS VistA cluster. This automatic time change feature should have been enabled during each VistA Cache conversion. Information on how to verify that an automatic time change will occur can be found in FORUM SHARED,MAIL basket AXP ALERT message: Subj: Addendum #2-AXP*157 OpenVMS Automatic Daylight Saving Time Adjust [#39819396] 10/23/04@09:51 154 lines Automated entries for the VMS time change may be either 02:00:00:00 or 02:01:30.00 and both entries are acceptable to accomplish the VMS time change. The time change will need to be done manually if it is not set to run automatically as described in the above text. Instructions to change time manually will be provided below in this text. On Sunday, October 31, around 1:50 AM shutdown VistA and Cache according to site-specific standard shutdown procedures. This includes the shutdown of Mumps AudioFax, Imaging, and Laboratory systems as well as other ancillary systems that communicate with VistA. A VMS shutdown is not necessary. To shutdown Cache on VMS enter the following command: $ CCONTROL STOP QUIETLY After Cache and VistA ancillary systems are shutdown wait at least an hour after the time change has occurred (for example wait until after 2:05 AM on the system clock). At the VMS level the time change can be observed by entering the following command at periodic intervals: $ SHOW TIME To monitor the time change cluster wide the following commands can be used: $ MCR SYSMAN SET ENVIRONMENT/CLUSTER SYSMAN> CONFIG SHOW TIME !Enter this command to see time on each node To monitor the time change from within Cache the following commands can be used: $ CSESSION LICENSE %SYS>D ^%T Note that the Cache "License" configuration will remain running during the time change process. If after 30 minutes of monitoring the time has not gotten set back, the time will need to be set back manually on each node of the cluster. The time can be set manually by using the following command procedure on each node of the cluster: $ @SYS$MANAGER:UTC$TIME_SETUP Cache is dependent on the UTC Time Setup so the above command procedure should be used to set the time if it needs to be set manually. Once an hour has elapsed after the fallback time change, VistA and other ancillary systems that communicate with VistA can be brought back on-line. The recommended way to restart VistA on each Cache/VMS system is as follows: $ @SYS$STARTUP:STARTUP$CACHE Then startup any other VistA processing according to site-specific standard startup procedures. This includes the startup of Mumps AudioFax, Imaging, and Laboratory systems as well as other ancillary systems that communicate with VistA. DSM/VMS Sites ============= Prior to Sunday, October 31 - DSM/VMS sites should either verify that an automatic time change will occur on the VMS VistA cluster or make arrangements to change the time manually. Instructions on how to verify if an automatic time change will occur are referenced in the above section of this text. If the time change is not set to take place automatically as described in the above text then the time change will either need to be done manually or according to automated procedures that have been used in the past on DSM systems. On Sunday, October 31, around 1:50 AM the DSM database can be "Write Inhibited" according to site-specific standard procedures as has been done in the past. If the DSM database is write inhibited then no action needs to be taken on other ancillary systems that communicate with VistA (such as Mumps AudioFax, Imaging, and Laboratory systems). A VMS shutdown is not necessary. To make the write inhibit process easiest is recommended to use Online Backup v3.1 commands write inhibit the DSM database. Online Backup v3.1 information can be found in FORUM SHARED,MAIL basket AXP Alert or on the VA intranet as follows: Subj: AXP*109 Release of Online Backup 3.1 [#31449272] 06/08/00 http://vaww.va.gov/custsvc/cssupp/axp/axp109.htm The Online Backup v3.1 commands are: To write inhibit all Volume Sets in the database: $ SET DEF ONL$BKUP $ DSM/MAN/E=DSMMGR/DATA="ONLINE_BACKUP.DAT" DIS^ZZJRNU After the VistA database is write inhibited wait at least an hour after the time change has occurred (for example wait until after 2:05 AM on the system clock). At the VMS level an automatic time change can be observed by entering the same commands as described in the Cache instructions above. To re-enable writes to the database after time change & waiting an hour: $ SET DEF ONL$BKUP $ DSM/MAN/E=DSMMGR/DATA="ONLINE_BACKUP.DAT" ENA^ZZJRNU Routine Information: ==================== ============================================================================= User Information: Entered By : METCALF,ROGER A Date Entered : OCT 22, 2004 Completed By: SINGH,GURBIR Date Completed: OCT 28, 2004 Released By : TILLIS,LEWIS Date Released : OCT 28, 2004 ============================================================================= Packman Mail Message: ===================== No routines included