Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Setting Up and Administering an HP-UX NFS Diskless Cluster
NFS Diskless Questions and Answers
Chapter 10 939
Question: My network becomes congested when booting many clients
simultaneously. What can I do?
Answer: When many diskless clients boot from one boot server simultaneously,
the server may be too busy to respond to each client’s boot request
quickly.
The default timeout values specified in each client’s /etc/fstab file take
into account large numbers of clients booting simultaneously. But your
network traffic may vary and you may want to do one or both of the
following:
• Adjust the timeout and retry values of the primary boot path for your
clients. HP recommends setting the primary boot path so that your
client does a directed boot request with infinite timeouts and retries.
Do this during the boot process on the client. If you have the older
type of ROM (RMP protocol), enter administrator mode (press the
escape key to interrupt the boot) and set the boot path as follows:
path pri lan. nnnnnn - nnnnnn .255.255
where nnnnnn - nnnnnn is the hardware address of the server system.
If you have BOOTP protocol ROMS (newer systems), set your path as
follows:
path pri lan. nnn . nnn . nnn . nnn .255.255
where nnn . nnn . nnn . nnn is the IP address of the server system.
• Distribute clients to multiple LANs to increase effective network
bandwidth. If this still does not help, then a faster server (or more
server RAM) may help.
Question: I built a new kernel on my diskless client and moved the old one to
vmunix.bak. The new kernel doesn’t boot for some reason, so I tried to
boot the old one by interacting with ISL. My system panicked. What is
wrong?
Answer: Two files are needed to boot an NFS diskless client: vmunix and
vmunix.fs. If you attempt to boot a kernel named XYZ, the secondary
loader will look for a second file named XYZ.fs. In this case, you need to
make sure that vmunix.bak is accompanied by vmunix.bak.fs, or the
system will not boot. A hard link or symbolic link to vmunix.fs should
suffice.