Please start any new threads on our new
site at https://forums.sqlteam.com. We've got lots of great SQL Server
experts to answer whatever question you can come up with.
| Author |
Topic |
|
rabensql
Starting Member
1 Post |
 Posted - 2012-03-08 : 02:50:09
|
| Dear all,I'm planning implementation of a new SQL infrastructure for my customer in the project department. Currently, I have really few information’s, which will come later from production department. I only know they currently have two 2 nodes clusters (one with SQL 2000 and one with SQL 2005). I also know that they are many databases on each server. They are low critical and medium critical databases. High critical production database are hosted on other DB servers.They want to migrate to a new architecture with 4 SQL 2008 R2 servers. They are 2 sites (Main and Data Recovery), VmWare VSphere 5 and SAN on each site will be used. SRM, HA and DRS will be implemented. I don’t know if FT will be implemented.I already work on VmWare ESX and with SQL Clusters, but never with both technologies in the same time. I also read that SQL Clustering in VSphere Cluster is not supported by DRS, and sometimes not recommended by experienced users, choosing SQL Mirroring.The goal is an architecture consolidation, upgrade, high availability and DRP solution. I currently have no diagram tools (only a pen and paper) but here is my architecture design:1 * 2 Nodes Cluster (Windows 2008 R2 Enterprise and SQL 2008 R2) on Main SiteShared SAN for cluster1 * 2 Nodes Cluster (Windows 2008 R2 Enterprise and SQL 2008 R2) on DR SiteShared SAN for clusterA High-Safety mode Session with Automatic Failover mirroring set from Main Site to DR Site.A Witness server ideally placed on a third site.Could you please advise me about this solution? Is it good? Bad? Is there a better way to complete the objectives? |
|
|
tajinder42
Starting Member
1 Post |
Posted - 2012-03-21 : 14:25:37
|
| Hi Raben,When you implement database mirroring for disaster recovery, you need to keep in mind that it is a database level DR solution not server level. We need to implement mirroring on each database. If an application is using more than one database simultaneously and we also want automatic failover, we need to look for another better solution. 1. Suppose any application is using three databases simultaneously, If somehow one database failover to DR site, then application will crash because it will not be able to access that database on production server. 2. If SQL Server is hosting a large number of databases say more than 40 then it will be very difficult to implement database mirroring. You need to calculate the base line based on your server hardware, what is maximum number of mirrored databases your hardware can support.You need to talk to application development team to find out how applications are accessing databases, can application automatically point to DR sites if not how much efforts are needed to point applications to DR site and then come up with DR solution and automatic failover to DR site. You can also search for Peer to Peer replication option for DR solution. |
 |
|
|
|
|
|
|
|
SQL Consolidation (Upgrade, DR, Virtualization)