rcdmqimg
Write the image of an object or group of objects to the log for media recovery.
Purpose
Use the rcdmqimg command to write an image of an object, or group of objects, to the log for use in media recovery. This command can be used only when using linear logging. See Types of logging for more information about linear logging. Use the associated command rcrmqobj to recreate the object from the image.
rcdmqimg must be run manually or from an automated task you have created. The command does not run automatically as it must be run in accordance with, and as determined by, the usage of each individual customer of IBM® MQ .
Running rcdmqimg moves the log sequence number (LSN) forwards and frees up old log files for archival or deletion.
- Disk space
- If disk space is limited, regular running of rcdmqimg releases log files for archive or deletion.
- Impact on normal system performance
- rcdmqimg activity can take a long time if the queues on the system are deep. At this time, other system usage is slower and disk utilization increases because data is being copied from the queue files to the logs. Therefore, the ideal time to run rcdmqimg is when the queues are empty and the system is not being heavily used.
You use this command with an active queue manager. Further activity on the queue manager is logged so that, although the image becomes out of date, the log records reflect any changes to the object.
Syntax
Required parameters
GenericObjName
- The name of the object to record. This parameter can have a trailing asterisk to record that any objects with names matching the portion of the name before the asterisk.
This parameter is required unless you are recording a queue manager object or the channel synchronization file. Any object name you specify for the channel synchronization file is ignored.
- -t
ObjectType
- The types of object for which to record images. Valid object types are:
Table 1. Valid object types Object Type Description all and * All the object types; ALL for objtype and * for GenericObjName authinfo Authentication information object, for use with Secure Sockets Layer (SSL) channel security channel or chl Channels clntconn or clcn Client connection channels catalog or ctlg An object catalog listener or lstr Listeners namelist or nl Namelists process or prcs Processes queue or q All types of queue qalias or qa Alias queues qlocal or ql Local queues qmodel or qm Model queues qremote or qr Remote queues qmgr Queue manager object service or srvc Service syncfile Channel synchronization file. topic or top Topics
Optional parameters
- -m
QMgrName
- The name of the queue manager for which to record images. If you omit this parameter, the command operates on the default queue manager.
- -z
- Suppresses error messages.
- -l
- Writes messages containing the names of the oldest log files required to restart the queue manager and to perform media recovery. The messages are written to the error log and the standard error destination. (If you specify both the -z and -l parameters, the messages are sent to the error log, but not to the standard error destination.)
When issuing a sequence of rcdmqimg commands, include the -l parameter only on the last command in the sequence, so that the log file information is gathered only once.
Return codes
Return code | Description |
---|---|
0 | Successful operation |
26 | Queue manager running as a standby instance. |
36 | Invalid arguments supplied |
40 | Queue manager not available |
49 | Queue manager stopping |
58 | Inconsistent use of installations detected |
68 | Media recovery not supported |
69 | Storage not available |
71 | Unexpected error |
72 | Queue manager name error |
119 | User not authorized |
128 | No objects processed |
131 | Resource problem |
132 | Object damaged |
135 | Temporary object cannot be recorded |
When are log extents deleted
Log extents are only deleted when the queue manager determines that they can be deleted. Note that log extents are not deleted immediately after recording the media image.
For example, if the starting media extent is 04
, the queue manager does not
delete this extent until the extent number moves forward, and the queue manager might or might not
delete extents 01
to 04
.
The logger event messages, and the IBM MQ queue manager error logs, show the log extents required for queue manager restart and media recovery.
Examples
saturn.queue.manager
in the log.
rcdmqimg -t qmgr -m saturn.queue.manager
Related commands
Command | Description |
---|---|
rcrmqobj | Recreate a queue manager object |