Click here to monitor SSC
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Database mirroring : Transaction log space pressure


Database mirroring : Transaction log space pressure

Author
Message
cygne17_2 77208
cygne17_2 77208
SSC Rookie
SSC Rookie (36 reputation)SSC Rookie (36 reputation)SSC Rookie (36 reputation)SSC Rookie (36 reputation)SSC Rookie (36 reputation)SSC Rookie (36 reputation)SSC Rookie (36 reputation)SSC Rookie (36 reputation)

Group: General Forum Members
Points: 36 Visits: 92
Hi,
With database mirroring, if the mirror database fails, the transaction log space on the principal database cannot be reused even if we are taking transaction log backup. This mean we need to have enough space for the transaction log to grow or bring mirror database online before the logs fills up the availabale disk space or break the database mirroring.

If we lost our principal database, and we force to switch on the mirror database with the "SET PARTNER FORCE_SERVICE_ALLOW_DATA_LOSS" command. After, the old mirror is now principal with the disconnected status because the old primary stil unavailable.

During this time and until the old principal become mirror and online, do I have a transaction log space pressure on the new principal ?

regards
kevaburg
kevaburg
Mr or Mrs. 500
Mr or Mrs. 500 (584 reputation)Mr or Mrs. 500 (584 reputation)Mr or Mrs. 500 (584 reputation)Mr or Mrs. 500 (584 reputation)Mr or Mrs. 500 (584 reputation)Mr or Mrs. 500 (584 reputation)Mr or Mrs. 500 (584 reputation)Mr or Mrs. 500 (584 reputation)

Group: General Forum Members
Points: 584 Visits: 923
I am not sure I understand exactly what you are asking.

If the mirror fails, the first thing I would do is break the mirror and check my backups to ensure I have no transaction log pressure.

If the principal fails, as you correctly pointed out, the mirror takes over but is advertised as disconnected. In this case as well, I would break the mirror and check my backups to remove the problems associated with transaction log pressure.

The command you posted does exactly what it says on the tin: Allows data loss which is the opposite of what high availability mirroring is about!

A failed mirror imho is no longer a mirror. Break it, fix the problem and reestablish the mirror as soon as you can. With a good backup plan your Transaction Logs remain reasonably small and you no longer have a problem!
Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search