Cluster Booting - What they dont tell you.

************************************** Episode 1 *********************************** This is as far as I got to this morning: I am beginning to wonder if everybody is talking and nobody is listening. ************************************************************************ *************** * The target machine is not running anything except low level firmware !!! * * No DECNet No Tcpip No VMS - Nothing !!!! (It can't-disk drives inoperable) * ************************************************************************ *************** However after wading around in sea of online manuals I think am beginning to find out the things they don't tell you. Given that there has to be some form of communication between the Boot server and the target. Then what's left is this MOP thing. As you can specify that the boot device is the ethernet adaptor (EZA0: in this case) when you try to boot from the target system it must be sending out some kind of request packet with an ID attached. It can't be a node name or an IP address. There's no way tell it what they are!! What it does know, is its MAC address which is hard encoded into the interface. The server has to respond to the request (Remember No Decnet and No Tcpip available) somehow or other. So what is it that runs on the server does not use Decnet or Tcpip and can load images into the target machine? We can rule out @SYS$MANAGER:CLUSTER_CONFIG_LAN which expects Decnet and screw's up TCPWARE. I'm out of ideas at this point. Rod Smallwood ************************************** Episode 2 *********************************** More wading around in on line manuals ... Then some light .... The key is a program called LANCP invoked as $MCR LANCP It allows you to associate a name say VAX300 with a MAC address and add it to a database. To do this it uses the DEFINE command. DEFINE NODE VAX300/ADDRESS=08-00-2B-18-BB-D0/FILE=APB_061.EXE This refered to as a NODE. Now the Boot server knows about the target machine and its MAC Address. So far so good.... Now for the other half of the puzzle. How does the boot server listen for requests. Well there's an executable program call LANACP that is invoked by running LAN$STARTUP.COM Once running it services boot requests from across the network. It uses the data from the data base maintained by LANCP. It gives progress messages when a Node tries to boot. ... and of course it works up to the point where it does not recognise the file name to down load (I have not found out what thats called yet) So.. 1. Hands up all of you who knew this and did not mention it. - Shame on you!!! 2. Hands up all of you that did not know this - Well, now you do!! 3. For MOP read LANACP. 4. Whats the name of the file to be downloaded from boot server to target to get VMS running on the target.? Lessons 1. Never run a .COM file before looking to see what it does. 2. Try and work out what needs to happen first. Rod Smallwood