GLS is a software product that enables high reliability communications through the use of multiple network interface cards (NICs) to create redundant multiple transmission paths to a local system. Global Link Services provides network solutions that are suitable for systems in which communications continuity is important.
The benefits of Global Link Services are as follows:
Multiple NICs can provide redundant transmission paths to offer high availability and path failure protection.
The use of GLS means that applications can continue to run even in the event of changes in the LAN configuration, the redundant transfer route, or any network fault that may occur in a transfer route.
GLS provides the following two functions:
Redundant Line Control Function
Fast switching mode
Multiplexing transfer routes between servers on the same network.
NIC switching mode
Configuring redundant transfer routes between servers and switches/HUBs on the same network.
Virtual NIC mode (Solaris)
Configuring redundant transfer routes between servers and switches/HUBs on the same network. By using the redundant route in the virtual environments (guest domain or non-global zone), the virtual server is effectively aggregated.
Virtual NIC mode (Linux)
Configuring redundant transfer routes between servers and switches/HUBs on the same network. By using the redundant route in the virtual environments (guest OS of the virtual machine function), the virtual server is effectively aggregated.
GS/SURE linkage mode (Solaris) and GS linkage mode (Linux)
Multiplexing transfer routes among the server on the same network, global server/SURE SYSTEM, and ExINCA.
Multipath mode (Solaris)
Multiplexing transfer routes between servers and switches on the same network.
Multilink ethernet mode (Solaris)
Distributing transfer data load on the multiplexed transfer route between servers and switches on the same network.
See
For details on the functions of Global Link Services, see "PRIMECLUSTER Global Link Services Configuration and Administration Guide: Redundant Line Control Function," "PRIMECLUSTER Global Link Services Configuration and Administration Guide: Redundant Line Control Function for Virtual NIC Mode," and "PRIMECLUSTER Global Link Services Configuration and Administration Guide: Multipath Function." The manual of virtual NIC mode and the manual of the multipath function are for Solaris only.
The transfer route is controlled by GLS own mode. In fast switching mode, the multiplexed transfer routes are used at the same time. If a fault occurs, the target transfer route is detached so that the system operation can be continued in a reduced scale.
Controlling transfer routes by GLS itself enables early fault detection. The compatible hosts are the Solaris server and the Linux server on which the fast switching mode is working. Except these hosts, communication with hosts is disabled. The fast switching mode cannot be used to communicate with hosts on the other networks beyond the router, either.
Figure 2.13 Fast switching mode
In NIC switching mode, duplexed NICs (LAN cards) are connected on the same network and switching of the transfer route is controlled using the NIC. There are no restrictions on the devices that can be connected, and it is possible to communicate with hosts on another network. To duplex the entire communication route, it is also necessary to duplicate the network equipment, such as routers, on the transfer routes and on all hosts because the duplexing of the paths should extend up to the direct connections to switches and HUBs.
Figure 2.14 NIC switching mode
