A T3 array contains nine disk drives, a single controller,  and the following interconnection interfaces:

Single host FC-AL interface
Single Ethernet 10BASE-T interface
Single RJ-45 serial port for admin
Single RS-232 serial service port
4 T3 array interconnect ports

T3 disk arrays can be configured in two modes: "workgroup" (Figure 1) or "enterprise " (Figure 2).


 Figure 1 Workgroup configuration
 


 Figure 2 Enterprise configuration
 



The "workgroup" mode is also known as "single controller unit" while the "enterprise" mode is called the "dual controller unit".

As a T3 array has only one controller/a single data I/O path, to support Sun Alternate Pathing (AP) version 2.3.1 and later,  or dynamic multipathing (DMP), a feature of VERITAS Volume Manager (tm) 3.0.2 and later, two T3 arrays have to be configured in Enterprise mode to form a partner group (pair) using interconnect cables as shown in Figure 2.

When T3 arrays are configured in Enterprise mode, one controller unit is referred to as the "master," while the other controller unit is called the "alternate master."  

DMP supported mode on T3s configured in Enterprise mode is active/passive.

Note: If you are using VERITAS Volume Manager Dynamic Multipathing for path management,  verify that the 'mp_support' (on the array) flag is set to 'rw.'

This can be done using a telnet session as a direct network link to the disk array. Once the session is open, run the following commands to verify DMP support: