-DISPLAY LOG (Db2)

The Db2 command DISPLAY LOG displays log information about the status of the offload task, the current checkpoint scheduling parameters, and the current active log data sets.

Abbreviation: DIS LOG

Environment

This command can be issued from a z/OS® console, a DSN session under TSO, a DB2I panel (DB2 COMMANDS), an IMS or CICS® terminal, or a program using the instrumentation facility interface (IFI).

Data sharing scope: Member

Authorization

To execute this command, you must use a privilege set of the process that includes one of the following privileges or authorities:
  • DISPLAY privilege
  • System DBADM authority
  • SYSOPR authority
  • SYSCTRL authority
  • SYSADM authority

Db2 commands that are issued from a logged-on z/OS console or TSO SDSF can be checked by Db2 authorization using primary and secondary authorization IDs. Start of changeA logged-on z/OS user ID must be defined in RACF or a similar security server.End of change

Syntax

Read syntax diagramSkip visual syntax diagramDISPLAY LOG

Usage notes

Information provided by the DISPLAY LOG command : You can use the DISPLAY LOG command to view the current checkpoint scheduling parameters and information about the current active log data sets and status of the offload task. You can obtain additional information about log data sets and checkpoint information by using the Print Log Map utility (DSNJU004).

Output

Message DSNJ370I indicates the beginning of the output of the command.

Examples

Example: Displaying log information
The following command displays information about the log and the status of any offload tasks.
-DISPLAY LOG

The output is similar to the following output:

DSNJ370I  -DT21 DSNJC00A LOG DISPLAY                        
CURRENT COPY1 LOG = DSNT2LOG.DT21.LOGCOPY1.DS07 IS 1% FULL  
CURRENT COPY2 LOG = DSNT2LOG.DT21.LOGCOPY2.DS07 IS 1% FULL  
          H/W RBA = 00000000405786F04E81                    
          H/O RBA = 00000000405772A28FFF                    
          FULL LOGS TO OFFLOAD = 0 OF 16                    
          OFFLOAD TASK IS (AVAILABLE)                      
          SOFTWARE ACCELERATION IS DISABLED                
          ZHYPERLINK WRITE IS ENABLED                      
            LAST LOG WRITE FOR COPY1 USED ZHYPERLINK        
            LAST LOG WRITE FOR COPY2 USED ZHYPERLINK        
DSNJ371I  -DT21 DB2 RESTARTED 15:53:15 OCT 15, 2021        
          RESTART RBA 00000000405784649000                  
          CHECKPOINT FREQUENCY 2 MINUTES                    
          LAST SYSTEM CHECKPOINT TAKEN 16:53:35 OCT 15, 2021
DSN9022I  -DT21 DSNJC001 '-DIS LOG' NORMAL COMPLETION

The output provides the following information:

  • The COPY1 active log data set is 1% full. The COPY2 active log data set is 1% full. If you are running dual logs and the percentages are different, the log data sets are of different sizes. Db2 switches both active logs when one reaches the end of the file. This can result in unused active log space if one log data set is larger than the other.
  • Db2 was started at 15:53:35 on October 15, 2021, and began logging at RBA 00000000405784649000.
  • Software acceleration is disabled for peer-to-peer remote copy.
  • Db2 zparm ZHYPERLINK is enabled for active logs.
  • If the ZHYPERLINK Db2 system parameter is set to ENABLE or ACTIVELOG, DFSMS does a zhyperwrite implicitly, even if the REMOTE_COPY_SW_ACCEL Db2 system parameter is not enabled.
  • Last log writes for COPY1 and COPY2 were done successfully using zHyperLink. To use zHyperLink Write for Db2, make sure that Db2 zparm ZHYPERLINK=ENABLE or ZHYPERLINK=ACTIVELOG and all the other hardware and DFSMS requirements are applied.
Start of changeExample: Displaying log information in a GDPS® Continuous Availability with zero data loss (GDPS Continuous Availability with zero data loss) environmentEnd of change
Start of changeIssue -DISPLAY LOG on a member of the source data sharing group in a GDPS Continuous Availability with zero data loss environment. Output like this is displayed. Message DSNJ375I indicates that the compression dictionary data set (CDDS) is in source mode.
DSNJ370I  - DSNJC00A LOG DISPLAY 
CURRENT COPY1 LOG = DSNC000.DB2A.LOGCOPY1.DS02 IS 1% FULL 
CURRENT COPY2 LOG = INACTIVE IS 0% FULL 
          H/W RBA = 000000000000471C3CD0 
          H/O RBA = 00000000000000000000 
          FULL LOGS TO OFFLOAD = 0 OF 3 
          OFFLOAD TASK IS (AVAILABLE) 
          SOFTWARE ACCELERATION IS DISABLED
          ZHYPERLINK WRITE IS ENABLED
            LAST LOG WRITE FOR COPY1 USED ZHYPERLINK 
DSNJ371I  - DB2 RESTARTED 11:22:42 DEC 28, 2018 
          RESTART RBA 000000000000471B7000 
          CHECKPOINT FREQUENCY 1000 LOGRECORDS 
          LAST SYSTEM CHECKPOINT TAKEN 11:22:46 DEC 28, 2018 
DSNJ375I  - DSNJC00A CDDS DSNAME = TEST.CDDS IS ACTIVE IN 
          SOURCE MODE. 
DSN9022I  - DSNJC001 '-DIS LOG' NORMAL COMPLETION

Issue -DISPLAY LOG on a member of the proxy data sharing group in a GDPS Continuous Availability with zero data loss environment. Output like this is displayed. Message DSNJ375I indicates that the compression dictionary data set (CDDS) is in proxy mode.


DSNJ370I  - DSNJC00A LOG DISPLAY 
CURRENT COPY1 LOG = DSNC000.DB2C.LOGCOPY1.DS02 IS 1% FULL 
CURRENT COPY2 LOG = INACTIVE IS 0% FULL 
...
DSNJ371I  - DB2 RESTARTED 11:26:13 DEC 28, 2018 
          RESTART RBA 00000000000000024000 
          CHECKPOINT FREQUENCY 1000 LOGRECORDS 
          LAST SYSTEM CHECKPOINT TAKEN 11:26:20 DEC 28, 2018 
DSNJ375I  - DSNJC00A CDDS DSNAME = TEST.CDDS IS ACTIVE IN 
          PROXY MODE. 
DSN9022I  - DSNJC001 '-DIS LOG' NORMAL COMPLETION
End of change
Start of changeFL 502 Example: Displaying log information about an encrypted data setEnd of change
Start of changeOutput like this is displayed for encrypted log data sets:

-DT41DIS LOG
DSNJ370I  -DT41 DSNJC00A LOG DISPLAY                              
CURRENT COPY1 LOG = DSNT4LOG.DT41.LOGCOPY1.DS02 IS 92% FULL        
KEY LABEL = DB2LOGKEY01                                                  
CURRENT COPY2 LOG = DSNT4LOG.DT41.LOGCOPY2.DS02 IS 92% FULL        
KEY LABEL = DB2LOGKEY01                                                  
         H/W RBA = 00000000427C46F74A97                          
         H/O RBA = 00000000427BCE396FFF                          
         FULL LOGS TO OFFLOAD = 0 OF 10                          
         OFFLOAD TASK IS (AVAILABLE)                              
         SOFTWARE ACCELERATION IS DISABLED                        
         ZHYPERLINK WRITE IS ENABLED                              
           LAST LOG WRITE FOR COPY1 USED ZHYPERLINK              
           LAST LOG WRITE FOR COPY2 USED ZHYPERLINK              
DSNJ371I  -DT41 DB2 RESTARTED 16:28:13 OCT 20, 2021                
         RESTART RBA 00000000427BB845E000                        
         CHECKPOINT FREQUENCY 2 MINUTES OR 500000 LOGRECORDS      
         LAST SYSTEM CHECKPOINT TAKEN 17:04:26 OCT 20, 2021      
DSN9022I  -DT41 DSNJC001 '-DIS LOG' NORMAL COMPLETION
End of change