SQL 2005 Database Mirroring in MOSS and WSS

Andrew Woodward MVP

Microsoft have released the white paper Using Database Mirroring with Office SharePoint Server and Windows SharePoint Services which is great news for most server farms. However I was interested to know if anyone has experience of this and if they have successfully used mirroring for MOSS with more than 10 databases, which is often the case when following MS best practice on content database sizing/seperation on larger farm deployments.

Andrew

Marcel Jeanneau

I've been trying to follow the whitepaper released by Microsoft about SQL Server 2005 Mirroring and MOSS (http://go.microsoft.com/fwlink/ LinkId=83725&clcid=0x409), but I've found that the document has a drastical error --it indicates that database mirroring session must be started from the principal server, and it must really be done from the mirror one. Ok let's pass it and move ahead (I could configure high availability mirroring with a witness server, finally) and when the backend fails over and I have to reconfigure MOSS, I follow the steps provided in the whitepaper but I can't reconnect to the Configuration Database, even though I have done

stsadm.exe -o renameserver -oldservername <SQLPRINCIPAL> -newservername <SQLMIRROR>

So I'm stuck here! I've tried to restart each and every service, restarted IIS, checked SQL Server services (mirror server active holding the active copies of the databases), I've run the MOSS configuration wizard first doing nothing but "Next .... next ..... next", then deattaching from the farm and reattaching again. Nothing. I've also tried with

stsadm.exe ¨Co setconfigdb ¨Cdatabaseserver <SQLMIRROR> ¨Cfarmuser <MYDOMAIN\MOSS_Service_Account> ¨Cfarmpassword <myFarmPassw0rd>

and get nothing. If I swith SQL roles back and use the stsadm.exe -o renameserver to reverse to the initial situation, then it works!! (MOSS back online). So what's wrong! I'm really stuck here. Two days by far.

Marcel Jeanneau

sbockheim

I have had a similar issue. In my case i can get the content database to be reconfigured, but the admin content datbase can not be moved off the principle. The stsadmin command does not reconfigure admin content database dsn (Where ever that is). Try leaving your admin content database on the principleand move the config. In my case all sites work except for the admin content.

I have an open question on how to change the pointer for the admin content database.

Scott

Rene Peinl

That's an interesting information since I've issued an official request to MS Germany regarding support for Sharepoint and SQL Server DB mirroring and received the answer that it is officially unsupported.
Nevertheless, I find the limitations severe enough to discourage any companies except very small ones to use the DB mirroring. An out-of-the-box MOSS installation already requires more than 5 DBs so the limitation to mirror 10 DBs is hit very fast. We have about a dozend content databases and made good experiences with using a MS cluster (active - active in our case). The only disadvantage is that you need a shared disk space.
Regards
Rene

Marcel Jeanneau

That mirror limitation of 10 databases is per session, it means you could have multiple sessions (endpoints) configured to support more than 10 databases. (I think )

andrew woodward

Marcel,

In not sure this is correct, the limiting factor (other posts on this forum) is around threads and the communication required between the servers in the mirror to keep it in step.

We are now looking at options for SAN replication (SQL Always On) or the option of having geospeperated SAN storage... Expensive

Otherwise log shipping will be the fall back postion failover SQL Clusters.

It's interesting to see that Microsoft is not supporting SQL Mirroring with SharePoint, they were the ones who release the white paper of the configuration for this.

Andrew

Marcel Jeanneau

I had no idea it wasn't supported. I emailed Joel Oleson telling him that the whitepaper is wrong in a couple steps because it's not working for me... Let me check that session limit thing because it's an important point about scaling database mirroring.