Do you have BOTH the SQL Nodes licensed?
I have found that it is easier to group BizTalk databases into the following Resource Groups (each resource Group is a separate Named Instance).
- BizTalk Management Resource Group - covers BizTalkMgmtDb and BizTalkRulesEngineDb
- BizTalk SSO Resource Group - only BizTalkSSODb
- BizTalk Message Box Resource Group - only BizTalkMessageDb
- BizTalk Archiving Resource Group - only BizTalkDTADb
- BizTalk Analysis Group - special because SQL Analysis Services needs to be installed into this resource group and covers all the BAM related database from BAMAlertsApplication to BAMAlertsNSMail to BAMPrimaryImport to BAMArchiveDb to BAMStarSchema.
- BizTalk Applications Group - host other databases such as EDI, A4SWIFT, etc. in this group.
To get maximum benfits, license both your SQL Servers and distribute these resource groups across the two servers. Configure one MSDTC per resource Group. Use tmMappingSet to assign the resource groups to clustered MSDTC.
The reasons are available in the BizTalk Operations Guide. DTA is a high r/w while BAM requires different access. MessageBox has high R/W while Management is Read Optimized.... so if you club this will appropriate SAN storage you would created an environment
more tuned towards performance.
Regards.