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stumbling
Posting Yak Master
104 Posts |
 Posted - 2009-05-28 : 05:09:29
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| Hi there if i set up mirroring and i have a really good machine as the principal a good machine as the mirroran ok machine as witnessif the principal goes down for a week how can i get the really good machine to once again become the principal? I have read http://technet.microsoft.com/en-au/library/cc917680.aspx and maybe i missed something but i could not see the way that the really good machine would be come the principal again.Am i correct in assuming the following?really good machine principal goes downgood machine mirror is promoted to principalok machine witness keeps goingif i bring really good machine back on line it now becomes the mirror correct?So if this theory is correct then is this how it worksreally good machine which is now the mirror stays ongood machine which is now the principal is turned offok machine witness keeps goingif i bring back the good machine it now becomes the mirror again correct or not?Sorry for the long winded explanation just a bit confused.Cheers |
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webfred
Master Smack Fu Yak Hacker
8781 Posts |
Posted - 2009-05-28 : 08:07:26
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I can not see in this moment, but I know there is a button to do a manual failover to change principal and mirror again.Webfred
No, you're never too old to Yak'n'Roll if you're too young to die. |
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mcrowley
Aged Yak Warrior
771 Posts |
Posted - 2009-05-28 : 09:39:28
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I would not intentionally bring a machine down to initiate a failover. You can use the ALTER DATABASE command to fail back to the really good machine when traffic is lower, and any impact to other applications can be minimized. One thing to note, you should check in sys.database_mirroring to make sure that the database is fully synchronized, before failing over. Otherwise, you may lose a bit of data.ALTER DATABASE [name goes here] FAILOVER |
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stumbling
Posting Yak Master
104 Posts |
Posted - 2009-05-28 : 17:39:25
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I would love to know where that is as i need to test the proccedure asap.Cheersquote:
Originally posted by webfred
I can not see in this moment, but I know there is a button to do a manual failover to change principal and mirror again.Webfred
No, you're never too old to Yak'n'Roll if you're too young to die.
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stumbling
Posting Yak Master
104 Posts |
Posted - 2009-05-28 : 17:41:51
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So what i could do is on the good server check to confirm that they are synchronised then run the alter database command then the really good server would be promoted back to the primary again. After that i could start the good server back up and it would then take the roll of the mirror server again.Correct?Cheersquote:
Originally posted by mcrowley
I would not intentionally bring a machine down to initiate a failover. You can use the ALTER DATABASE command to fail back to the really good machine when traffic is lower, and any impact to other applications can be minimized. One thing to note, you should check in sys.database_mirroring to make sure that the database is fully synchronized, before failing over. Otherwise, you may lose a bit of data.ALTER DATABASE [name goes here] FAILOVER
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mcrowley
Aged Yak Warrior
771 Posts |
Posted - 2009-05-29 : 09:41:29
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| Nope. No reboots are necessary. When you issue the ALTER DATABASE command, the primary becomes the mirror, and the mirror becomes the primary. |
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