jerzy@scotty.dccs.upenn.edu (Jerzy Sliwinski) (01/05/89)
We are asking people at educational institutions to participate
in a survey concerning your use of Network File Systems (NFS) software.
We are anticipating that our utilization of NFS products will increase
in the future and are attempting to better understand their impact on
our network. We would appreciate it if you would take the time to fill
out the questionnaire and return it to us by Monday, January 23, 1989.
Please send responses via E-Mail to Survey@UPENN.EDU.
We will provide you with the results of the survey when completed.
In order to clarify the information being requested in the survey,
we have also attached a completed sample survey. Please refer to it if
the intent of any of the questions is unclear. If you have specific
questions, please send E-Mail to the above mentioned address or call me
at (215) 898-9308.
Thank you in advance for your participation.
Jerzy Sliwinski
University of Pennsylvania
Data Communications and Computing Services
Suite 221A, 3401 Walnut Street
Philadelphia, PA 19104-6228
phone #(215)898-9308
jerzy@dccs.upenn.edu
*************** begin survey **************************************
GENERAL QUESTIONS
- Are you using TCP/IP over Ethernet connected by routers and/or bridges and
if so briefly describe your Network Architecture.
- If not, describe your Network
- Bandwidth
- Campus wide connectivity strategy
- What are the major protocols used on the Network
- Estimate % use of each major protocol
NETWORK FILE SYSTEM QUESTIONS
- How many hosts at your site are using NFS (complete the table below)
Principle NFS # Projected in
Function Vendor Hardware/OS Version # Today One Year
*Disc Server
*Diskless Clients
*Dataless Clients
*Standalone Clients
- Describe any problems encountered with NFS
- What performance bottlenecks have you observed while using NFS?
- Describe any new bottlenecks you expect in a year. Consider
availability of faster client and server hardware
- If your Network isn't the bottleneck, now under what situation would
it be?
- If you had a faster Network would you use NFS differently?
- Describe any ambitious use of NFS: specifically; purpose,
describe this configuration, list number and type of servers and
clients, describe any specialized networking in this application,
explain how you isolate traffic, (e.g. separate NFS Ethernet,
filtering bridges, IP routers).
- Briefly note any other observations you have regarding use of NFS.
*Definition of terms:
Disk Server - System which main function is to offer its disk accessible
to other systems on the Network via NFS protocol.
Diskless Clients - Systems that do not have a disk, they do all the disk
access via Network.
Dataless Clients - System with a small disk. The disk is used for swapping,
temporary files and some files that do not change and do
not require backup. The rest of the files are stored on
the disk server.
Both diskless and dataless clients require the file server
to boot.
Standalone Clients - System that does not need the presence of the server
on the Network to boot. It uses the server for some
of the files. It may also act as the file server.
*********** end survey ************************************************
Completed sample survey:
GENERAL QUESTIONS
- Are you using TCP/IP over Ethernet connected by routers and/or bridges and
if so briefly describe your Network Architecture.
Our network is composed of 12 cisco routers interconnected by point
to point ethernet bridges (DEC DEBETs and DELNIs).
- If not, describe your Network
- Bandwidth
- Campus wide connectivity strategy
- What are the major protocols used on the Network
- Estimate % use of each major protocol
IP 80%
DECnet 15%
XNS 4%
other 1%
NETWORK FILE SYSTEM QUESTIONS
- How many hosts are using NFS (complete the table below)
Principle NFS # Projected in
Function Vendor Hardware/OS Version # Today One Year
*Disc Server
SUN 3/280 SunOS 4.0 3 4
*Diskless Clients
SUN 3/60 SunOS 4.0 17 40
*Dataless Clients
SUN 3/60 SunOS 4.0 5 20
*Standalone Clients
DEC microVAX Ultrix 2.2 5 10
- Describe any problems encountered with NFS
We noticed problems when too many clients tried to use the server.
Cross mounting file systems, that is A mounts files of B while B mounts
files on A, creates unexpected dependencies, making it hard to reboot either
A or B and recover.
- What performance bottlenecks have you observed while using NFS?
The familiar message "NFS server not responding". Some of these are just
over-anxious clients, but some are indicative of problems.
- Describe any new bottlenecks you expect in a year. Consider
availability of faster client and server hardware
As always, servers are the usual bottleneck. As clients become faster,
their appetite for data increases. Also, I haven't seen the figures for
ethernet utilization, but expect that may start to be a problem.
- If your Network isn't the bottleneck, now under what situation would
it be?
I think that diskless workstations that use the network for both paging and
file access are the biggest users of network resources. I don't know what are
the number of clients and servers that can be accommodated on a single
ethernet. As the number and speed of workstations increases the network may be
a potential bottleneck.
- If you had a faster Network would you use NFS differently?
Local use probably would not change significantly. A faster, more reliable
campus backbone might allow more cross-campus NFS mounting. A faster WAN would
allow cross-country mounting. This could be useful with internet archives.
- Describe any ambitious use of NFS: specifically; purpose,
describe this configuration, list number and type of servers and
clients, describe any specialized networking in this application,
explain how you isolate traffic, (e.g. separate NFS Ethernet,
filtering bridges, IP routers).
We have a cluster of diskless workstations (17 SUN 3/60s) served by 2
file servers (SUN 3/280s). This cluster is used by graduate students.
While installing and configuring this cluster we realized that
we would like to be able to give users an account that could be used on
any of the workstations and give the user access to his files.
My long term goal for the CIS department and possibly for the School of
Engineering and Applied Science (SEAS) is to have everyone have one account
which they can use on any machine. File system and cpu will become
separable resources from the users' perspective.
- Briefly note any other observations you have regarding use of NFS.
So far, we have not seen any serious incompatibility between different vendor's
NFS implementations.