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: : Be sure to modify the PC's entry in BOOTCONF.SYS to refer to the menu
boot filename in place of the original boot image filename. If
BOOTCONF.SYS is not used, name your menu boot file NET$DOS.SYS.
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When multiple servers exist on a network, MBA must know the server from which to obtain
the boot information.
To indicate which server is to be used, MBA includes an optional server NLM called MSD
(Multi Server Director). If the MSD option is enabled in the MBA configuration, MBA attempts
to locate a server running the MSD NLM. If located, this server directs MBA to the proper
server and image to boot from.
If a server running MSD NLM cannot be located or the MSD option is disabled, MBA locates
the nearest server and attempts to boot from that server.
Because of the random nature of finding a particular server (it depends on how busy a server
is, and how quickly it responds), it is absolutely necessary that you copy all boot image files,
AUTOEXEC and other .BAT files, and BOOTCONF.SYS files across all file servers in your
internetwork. Failure to do so may cause MBA to occasionally issue an “Error Opening Boot
File” message as it connects to a server that doesn't contain the required boot image files.
With the MSD NLM option, you can specify the file server(s) from which an MBA-equipped PC
will boot, and maintain boot image files only on the designated servers.
A full-featured MSD NLM is provided with MBA. This version is unrestricted and includes
activity logging.
How MSD Works
At boot time, MBA-equipped PCs first broadcast a “Get nearest MSD” request. See Figure 17.
One or more file servers reply with the address of the nearest MSD NLM. MBA then sends a
request to the MSD NLM asking for the name of the server and image file. Upon receiving
this request, the NLM looks for the PC's boot information in the BOOTCONF.SYS file. If a
matching entry is found, MSD replies to the MBA PC with the information.
If no matching PC entry is found, MSD replies with the name of a boot image file which is
specific to the PC's type of NIC (except in cases where the NODEFAULT option is used). You
can obtain the ROMTYPE number from the MBA Information screen. Also see “Other Tools:
ROMTYPE: Conditional Execution based on MBA Type ” in this chapter.
If the PC receives no reply from the MSD NLM in two seconds, MBA defaults to its normal
mode of operation and attempts to boot from the nearest file server.