What will happen when set partner to a database ?

Question

As you know, One database can mirror with one and only one another database.  There is an interesting thing when I setup a mirror ha between server a and server b, I make a third database at server c using the backups from server a including transaction log backups. The database is in restoring state. And I can set up the partner of server c to server a. 

My question is what will happen when I set the partner of c to a.

Answer 1

did u use server c to monitor the mirroring,

if you are impelmenting backup ,copy ,resore between server a and server c, then not possibe,

as there is a port level communications between server a and server b , it is not possible to impleten it

---

Ramesh Babu Vavilla MCTS,MSBI

Answer 2

No,  I just init server c using the backups of server a.

1. backup server a

USE MASTER
GO
BACKUP DATABASE [lgwdb1] TO DISK = 'd:\backup\lgwdb1.BAK' WITH INIT
GO
BACKUP LOG [lgwdb1] TO DISK = 'd:\backup\lgwdb1.TRN' WITH INIT
GO

copy the backup to server c [10.250.14.9]

2. restore the backup at server c

USE MASTER
GO
RESTORE DATABASE [lgwdb1] FROM DISK = 'D:\backup\lgwdb1.BAK' WITH NORECOVERY,
REPLACE,
MOVE 'data1' TO 'D:\ms3003\data\lgwdb1\lgwdb1.MDF',
MOVE 'log' TO 'D:\ms3003\log\lgwdb1\lgwdb1_LOG.LDF'
GO
RESTORE LOG [lgwdb1]FROM DISK = 'D:\backup\lgwdb1.trn' WITH NORECOVERY, REPLACE
GO

the state of database lgwdb1 at server c is "Restoring"

then I set the partner of server c to server a:

ALTER DATABASE [lgwdb1] SET PARTNER = 'TCP://10.250.14.7:23008'
GO

the state of database lgwdb2 at server c changes to "In Recovery"

what has happened?

Answer 3

no u cannot add a new port after mirroring is established, it gives a error that port you are using i already used in mirroring.

---

Ramesh Babu Vavilla MCTS,MSBI

Answer 4

I am not sure that I get the point, but let me try a hunch:

When you run the SET PARTNER command your supposed mirror (server C) tries to establish a connection to server A. After that connect it waits for Server A to confirm the mirroring connection to switch into mirror mode. As Server A is still mirroring with Server B it will not acknowledge this, so Server C stays in this intermittent state...

Lucifer

Answer 5

I am not sure that I get the point, but let me try a hunch:

When you run the SET PARTNER command your supposed mirror (server C) tries to establish a connection to server A. After that connect it waits for Server A to confirm the mirroring connection to switch into mirror mode. As Server A is still mirroring with Server B it will not acknowledge this, so Server C stays in this intermittent state...

Lucifer

Yes you are right. I found nothing happened.