3.4.0 Matrix Server Command Reference

Chapter 2: mx Commands 82

--msdtc

Microsoft Distributed Transaction Coordinator (MSDTC) is used to

coordinate transactions between different SQL instances running on

different nodes in the cluster. There is one MSDTC service on each machine.

This option enables transactions that span one or more Virtual SQL Servers.

However, the following limitations exist when using a Virtual SQL Server

with MSDTC:

• Because only one MSDTC resource exists per machine, you can define

MSDTC support for only one Virtual SQL Server per machine. You can,

however, define other Virtual SQL Servers that do not support MSDTC.

The PolyServe Management Console will grey out the MSDTC switch

when a Virtual SQL Server has already been defined as primary on this

node.

• If two MSDTC-enabled Virtual SQL Servers share the same backup and

both Virtual SQL Servers fail, the first server to come up will lock the

MSDTC resource, preventing the other Virtual SQL Server from starting.

• A failure of MSDTC is considered a failure of the SQL instance.

• You cannot use COM+ components or MSMQ on a node where MSDTC

has been virtualized.

For more information about MSDTC, see the PolyServe Knowledge Base

article “Configure or Rebuild MSDTC on Windows 2003.”

<ip> is the IP address for the SQL Virtual Server. <name> is the NetBIOS

name for this Virtual SQL Server; the name can include up to 15 characters.

The order in which you specify the network interfaces determines the

ordering for failover. The first network interface is the primary interface;

network traffic for the Virtual SQL Server goes to the node providing this

interface. The remaining network interfaces are backups. Each network

interface must be located on a different node.

Modify (update) an existing Virtual SQL Server:

mx vsql update [--policy nofailback|autofailback] [--application

<application_name>] <ip> <name> ([<network_interface> ...])

The options are the same as vsql add except that the --msdtc option is not

supported.