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

Planning a Workgroup
Distributing Applications and Data
Chapter 2 65
File Server
Users normally do not log in to a file server; they get the data they need
from it by means of NFS mounts.
The main requirements for a file server are:
• plenty of disk space
Disk striping, which allows I/O to multiple spindles concurrently,
may improve throughput.
• plenty of RAM
• fast I/O interfaces such as Fast-Wide SCSI.
• proximity to the workstations it serves
Intervening hubs, routers, switches and busy LAN segments will
slow things down.
This list is not meant to imply that CPU power is not important in a file
server, only that it is not as important as it is in application server.
Application Server
If you have, or can afford to buy, the hardware resources, you should
install applications on a system to which users can log in and run them.
Whether they do or not will depend partly on how much power and
capacity they have on their desktops, partly on LAN performance, partly
on OS/application compatibility; but it’s likely that at least some users in
the group will not be able to run all the applications they need locally,
and others will prefer not to because, for one reason or another, local
performance is poor. And of course some applications, such as large
database applications, by their nature require capabilities not likely to
be found on anyone’s desktop.
An application server, then requires:
• All the characteristics of a file server, because in some cases it acts as
a file server, distributing applications via NFS to clients that run
them locally.
For performance reasons, this is probably not an ideal arrangement
(the applications are likely to run faster if the server’s CPU is not
busy handling NFS requests) but it’s a common one, and in practice
it may work well.