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| velocity |
 Posted: Mon Feb 25, 2008 8:05 am Post subject: Backup & recovery |
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Centurion
Joined: 30 Nov 2007
Posts: 126
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Hi guys,
I was going through the MQ backup-recovery guide and got the following question..
Here is what I understand
There are three ways you can take backups (Media/object backups)
1) By using linear logging.
2) By taking backups using saveqmgr
3) By using rcdmqimg -m QM_NAME -t all *
Did I get it right?? Correct me if I am wrong pls.
Thanks in advance! |
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| Vitor |
| Posted: Mon Feb 25, 2008 8:09 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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Linear logging is not a backup per se - it just allows the queue manager to roll forward after a failure. The rcdmqimg command is used in conjunction with a linear log to create a new roll-forward image in the logs and free up earlier ones. The saveqmgr app will create a script of the objects within a queue manager, but will not backup the queue contents.
You'd use something like the q program to back those up. Other methods equally valid, etc, etc including of course the linear log rolling forward.
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| velocity |
| Posted: Mon Feb 25, 2008 8:19 am Post subject: |
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Centurion
Joined: 30 Nov 2007
Posts: 126
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| Quote: |
| The rcdmqimg command is used in conjunction with a linear log to create a new roll-forward image in the logs and free up earlier ones. |
Now the abvious question is:
1) Implementing the situation above, can I do away with using saveqmgr?? If not what is saveqmgr going to do differently for me?
2) What is the q program?
Regards,
Velovity |
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| jefflowrey |
| Posted: Mon Feb 25, 2008 8:20 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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1) linear logging doesn't provide "backups"
2) MS03 only provides a backup of your MQSC object definitions
3) rcdmqimg doesn't provide "backups". It causes the linear logging to synchronize the log files so that the active set is small.
If you need a backup of your queue manager or your messages then you need to stop the queue manager and take a file system backup.
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I am *not* the model of the modern major general. |
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| Vitor |
| Posted: Mon Feb 25, 2008 8:28 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| velocity wrote: |
| 1) Implementing the situation above, can I do away with using saveqmgr?? If not what is saveqmgr going to do differently for me? |
It allows you to take an externalised copy of your objects. Redundant if your linear logs can't be corrupted (because they're RAID / mirrored /etc)
| velocity wrote: |
2) What is the q program?
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A support pac that does for the contents of queues what saveqmgr (another support pac) does for the definitions. The Search Button Is Your Friend. 
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| Vitor |
| Posted: Mon Feb 25, 2008 8:31 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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And if you're talking DR then the only thing that works is what jefflowrey has suggested OR a full unload with q & saveqmgr to get the information off-site.
And in that scenario, it's cleaner to do a point-in-time backup of the file system as he says.
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| velocity |
| Posted: Mon Feb 25, 2008 8:43 am Post subject: |
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Centurion
Joined: 30 Nov 2007
Posts: 126
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| OH ok...Got it!! Thanks guys for your input on this!! |
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| jefflowrey |
| Posted: Mon Feb 25, 2008 8:44 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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For DR, you should be looking at the "backup qmgr" option in v6.
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| PeterPotkay |
| Posted: Mon Feb 25, 2008 5:04 pm Post subject: |
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Poobah
Joined: 15 May 2001
Posts: 7722
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And think about how useful a point in time full backup of the file system with the QM down is going to be.
1 second after you finish the backup and start the QM new messages arrive in the queues and old ones are removed. If you then go to restore from your backup you introduce duplicate messages and missing messages. So how useful was that?
MQ is not a database.
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Peter Potkay
Keep Calm and MQ On |
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