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

Administering a System: Booting and Shutdown

Shutting Down Systems

Chapter 5528

Special Considerations for Shutting Down Certain

Systems

In today’s world of networked computers, people who are not direct users

of your system can still be affected by its absence from the network

(when it has been shut down). If your system is serving one or more of

the following functions, you need to at least consider the impact to users

of other systems when you plan to take your system down; and, if

possible, you should try to let them know in advance that they will be

affected, so that they can prepare for the event.

Mail Server

If your system is a mail server, it receives e-mail on behalf of its users,

and is often the computer handling the outgoing e-mail for them too.

When your system is down, incoming mail is usually held by other

computers in the network for delivery when your system is back on line.

If your computer will be down for an extended period of time, it is

possible that others sending e-mail to your computer’s users will have

their e-mail returned as being undeliverable.

And, of course, users receiving e-mail through your system will not be

able to do so while your system is down.

Name Server

If your computer is a network name server (for example, a DNS name

server), it is responsible for translating computer alias names into IP

addresses for its own users and those who have conﬁgured their systems

to use your computer as their name server. Usually systems are

conﬁgured to use multiple sources for name switch information so if

your system is down, they can use an alternate name server, a local

hosts ﬁle, or directly use IP addresses to access remote machines until

your system is back on line.

You can conﬁgure which systems (or other sources) a computer will use

to map computer names to IP addresses by using SAMs “Networking and

Communications/DNS (BIND)/DNS Resolver” area, or by editing the ﬁle

/etc/resolv.conf. Using SAM is the preferred method.