February 18, 2014 at 4:28 am
Hi,
I have one database which is of 80 GB on SQL 2005 Standard Edition. On this database mirroring-synchronous mode, no automatic failover is configured.
If production server goes down (due to some reason) manual failover will will be done by executing below command on Mirror server.
Alter Database [DBNAME] SET PARTNER FORCE_SERVICE_ALLOW_DATA_LOSS
Now the Mirrored database will become Principal database
After 2-3 days the production server is up and there is no corruption issue with the database. My doubt is the transactions committed or objects created at current principal server (earlier mirror) in these 2-3 days will they be replicated or send to Mirrored database (earlier principal) ?
What kind of synch status will be there between these two databases?
Thanks in advance
Nikhil P Desai
February 18, 2014 at 5:23 am
As soon as the new Mirror (former Principal) is back online, the mirroring session will resume and the Mirror will be in a Synchronizing state. All the transactions that are queued up at the current Principal will be sent to the new Mirror and once they've all been applied, the Mirror status will change to Synchonized. You won't lose any data, but the transaction log on the current Principal will continue to grow until the mirroring session resumes so make sure you have sufficient space for your anticipated period of downtime.
Where data loss may occur is during the manual failover (hence the command ends with ALLOW_DATA_LOSS), but as you are running in synchronous mode, that risk is reduced.
Regards
Lempster
March 11, 2014 at 1:22 am
Hi,
Suppose in this 2-3 days FULL , DIFF and Trn backup is taken at B(earlier Mirror). After 2-3 days when A(earlier Principal) is up then whether the database backup taken at B(earlier mirror) will affect database mirroring synchronization.
Thanks and Regards,
Nikhil Desai
March 11, 2014 at 10:54 am
It shouldn't affect.
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SQLBuddy
March 13, 2014 at 10:24 am
Lempster (2/18/2014)
As soon as the new Mirror (former Principal) is back online, the mirroring session will resume and the Mirror will be in a Synchronizing state.
The mirror session will be supsended it won't auto resume. You have to actually tell it to resume, this acts as confirmation you want the old Principal to continue as a mirror partner
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