You keep mentioning configuring the DSM.OPT file with the "addresses". Why not use a name and let DNS resolution take over. Then to move things around, just change DNS. You could try out lots of different scenarios without having to keep changing the DSM.OPT files on all your clients.
Bill Boyer DSS,Inc. -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED]]On Behalf Of Thomas Denier Sent: Friday, August 30, 2002 11:53 AM To: [EMAIL PROTECTED] Subject: Mainframe networking We have a TSM 4.2.1.9 server running under OS/390 Version 2 Release 9.0. We are in the process of migrating to a new network infrastructure. The old network has Ethernet connections to Unix and Windows hosts, an ATM backbone, and an ATM OSA card in the mainframe to provide network connectivity for TSM. The old network uses 3COM Ethernet switches, routers, and ATM switches. The new network will use Ethernet throughout, and will have two Ethernet OSA cards in the mainframe to provide network connectivity for TSM. Our mainframe does not support gigabit per second OSA cards. The new network will use Cisco switches and routers. We are planning to add three new address to the TCP stack supporting the TSM server: one for each of the new OSA cards and one virtual (VIPA) address. We will leave the address for the old OSA card in place until migration is complete. The campus routing infrastructure will treat each of the three addresses associated with hardware interfaces as routers capable of forwording packets to the virtual address. We will update the dsm.opt (Windows) or dsm.sys (Unix and Linux) file on each client to specify the virtual address as the address of the TSM server. There is going to be a transitional period when some incoming traffic will be routed through the ATM card on its way to the virtual address and other incoming traffic will specify the ATM card as the ultimate destination. The documentation seems to imply that the card can play this dual role successfully. Can anyone who has done a similar migration confirm this? We will eventually end up with all traffic on the two Ethernet OSA cards. Ideally, the routing infrastructure would split the flow of inbound packets equally between the two cards. The people who install and configure the mainframe TCP/IP stack think this will happen. The people who run the campus network do not. If the latter group is right we will have to split the dedicated subnet for backup traffic into two subnets and try to divide the client systems in a way that splits the packet volume more or less equally. Has anyone achieved dynamic load splitting between two mainframe network interfaces, or attempted it and concluded that it was impossible?
