HP OpenVMS System Manager's Manual, Volume 2:...

Managing DECdtm Services

Changing the Size of a Transaction Log

Dismounting a Disk

Moving a Transaction Log  

• You want to place the transaction log on a faster disk



• You want to redistribute the work load on your disks

How to Perform This Task

Follow all the steps carefully. Taking shortcuts can lead to data corruption.

1. Decide the location that you want to move the transaction log to, using the guidelines in Deciding the Location of a Transaction Log. Remember that the disk must have enough contiguous space to hold the transaction log.
2. Log in to the node that the transaction log belongs to.
3. If you are in an OpenVMS Cluster, make sure that the disk you want to move the transaction log to is mounted clusterwide.
4. Decide which directory you want to move the transaction log to. You may want to create a new directory for the transaction log.
5. Find out which directory the transaction log is in, using LMCP's SHOW LOG command:SHOW LOG SYSTEM$node.LM$JOURNALwhere node is the name of the node that the transaction log belongs to.
6. Rename the transaction log: RENAME dirspecSYSTEM$node.LM$JOURNAL dirspecSYSTEM$node.LM$OLD where:

   dirspec	is the full specification of the directory containing the transaction log.
   node	is the name of the node that the transaction log belongs to.

   
   

7. Can you stop all the software that uses DECdtm services without shutting down any nodes?

   Yes

   Close the transaction log as follows: Step   Action a.   Stop all the software that uses DECdtm services. b.   Close the transaction log using LMCP's CLOSE LOG command: $ RUN SYS$SYSTEM:LMCP LMCP> CLOSE LOG The CLOSE LOG command closes the transaction log and stops the DECdtm TP_SERVER process. The command fails if any software is using DECdtm services. c.   Did the CLOSE LOG command succeed? Yes   Restart the TP_SERVER process: $ @SYS$STARTUP:DECDTM$STARTUP.COM No   Wait for 30 seconds, then repeat steps 7b and 7c.

   No

   Close the transaction log by rebooting the node. Log in to the node when it has rebooted.

   
   

8. Make sure that SYS$JOURNAL points to the directory that you want to move the log to. If SYS$JOURNAL does not point to this directory, redefine SYS$JOURNAL: DEFINE/SYSTEM/EXECUTIVE_MODE SYS$JOURNAL dirspec[,...] where dirspec is the full specification of a directory containing one or more transaction logs. List all the directories that will contain transaction logs after you have moved the transaction log. You can list the directories in any order.
   
   In an OpenVMS Cluster, use SYSMAN to redefine SYS$JOURNAL clusterwide.
9. If you redefined SYS$JOURNAL in step 8, edit the SYS$MANAGER:SYLOGICALS.COM command procedure to update the definition of SYS$JOURNAL.
   
   If you created node-specific versions of SYLOGICALS.COM, edit all the versions.
10. Move the transaction log, using LMCP's CONVERT LOG command: CONVERT LOG old-dirspecSYSTEM$node.LM$OLD new-dirspecSYSTEM$node.LM$JOURNAL where:

    old-dirspec	is the full specification of the directory that currently contains the transaction log.
    node	is the name of the node that the transaction log belongs to.
    new-dirspec	is the full specification of the directory that you are moving the transaction log to.

    
    

11. If you stopped the software that uses DECdtm services in step 7, restart the software.
12. Delete the old transaction log: DELETE dirspecSYSTEM$node.LM$OLD;where:

    dirspec	is the full specification of the directory containing the old transaction log.
    node	is the name of the node that the transaction log belongs to.

    
    

Example

This example shows how to move BLUE's transaction log. BLUE is in an OpenVMS Cluster. The cluster members and the locations of their transaction logs are as follows:

Node	Directory Containing Log
BLUE	DISK$LOG1:[LOGFILES]
RED	DISK$LOG2:[LOGFILES]

Neither node has a node-specific version of SYLOGICALS.COM.

Decide where you want to move BLUE's transaction log to. In this example, assume that you want to move it to DISK$LOG3:[LOGFILES].

Log in to node BLUE. Then mount the disk clusterwide, and create a new directory for the transaction log:

$ MOUNT/CLUSTER/SYSTEM DUA3: LOG3
$ CREATE/DIRECTORY DISK$LOG3:[LOGFILES]

$ RUN SYS$SYSTEM:LMCP
LMCP> SHOW LOG SYSTEM$BLUE.LM$JOURNAL

Directory of DISK$LOG1:[LOGFILES]
 
SYSTEM$BLUE.LM$JOURNAL;1
 
Total of 1 file.
LMCP> EXIT
$ RENAME DISK$LOG1:[LOGFILES]SYSTEM$BLUE.LM$JOURNAL -
_$ DISK$LOG1:[LOGFILES]SYSTEM$BLUE.LM$OLD

$ RUN SYS$SYSTEM:LMCP
LMCP> CLOSE LOG
Transaction log closed, TP_SERVER process stopped
LMCP> EXIT

$ @SYS$STARTUP:DECDTM$STARTUP.COM

$ RUN SYS$SYSTEM:SYSMAN
SYSMAN> SET ENVIRONMENT/CLUSTER
SYSMAN> DO DEFINE/SYSTEM/EXECUTIVE_MODE SYS$JOURNAL -
_SYSMAN> DISK$LOG2:[LOGFILES], DISK$LOG3:[LOGFILES]
SYSMAN> EXIT

$ RUN SYS$SYSTEM:LMCP
LMCP> CONVERT LOG DISK$LOG1:[LOGFILES]SYSTEM$BLUE.LM$OLD -
_LMCP> DISK$LOG3:[LOGFILES]SYSTEM$BLUE.LM$JOURNAL
Log file DISK$LOG3:[LOGFILES]SYSTEM$BLUE.LM$JOURNAL;1 created.
Log file DISK$LOG1:[LOGFILES]SYSTEM$BLUE.LM$OLD converted.
LMCP> EXIT

$ DELETE DISK$LOG1:[LOGFILES]SYSTEM$BLUE.LM$OLD;

Changing the Size of a Transaction Log

Dismounting a Disk