Hi managers. Our AlphaStation 255/233Mhz (DU4.0D) server is having some
problems with sharing out several disk areas to a reasonably sized network
(around 50+ clients), with reports coming back saying that read/write
times to NFS mounts are extremely slow, some saying around 10 times slower
than writing to the local disk. We have the server on a switched port
(100MBit) and although we have a fair amount of network traffic on this
subnet, I wouldn't say it's anything too much to handle, so I'm looking to
the server for possible causes for poor performance.
I've been going through sys_check output, man pages on NFS setup, and I've
come up with some ideas on improving NFS, but I'm not sure about values to
use and I'd like some expert opinions on ways to better it.
We have primarily Linux hosts working with the server, but we also have
SGI/Sun/Windows hosts as well. They all seem to be talking via UDP and NFS
V2, even though SGI and Sun should default to NFS V3 and TCP. I'm thinking
of forcing the use of TCP and NFS V3 (where possible).
First question: in an environment of around 50+ clients, what's the best
setup to use? UDP -v- TCP NFS V2 -v- V3?
The nfs_manual_setup man page suggests doing the following:
- increase the number of nfsd's running to improve responsiveness. It says
you can define the number that talk UDP/TCP.
Second question: How many is a good figure to use? I'm currently using the
default of 12 for each (UDP/TCP) - is this enough for 50+ clients, or
should I look to use more? How many more?
- if read/write performance is poor, increase the number of nfsiod's
running (which is the case here)
Third question: The server is using the default of 7 - same as for Q2.
If there are web pages out there that talk about all this, please pass
them on, otherwise people's experience/thoughts will be appreciated. Poor
NFS performance has been an issue for some time, and users are getting to
their wits end on this, so a resolution is required soon.
Thanks,
------------
Greg Roberts
Computer Systems Officer
Dept. of Electrical & Electronic Engineering
The University of Western Australia
NEDLANDS WA 6907 Australia
Ph : +61-08-9380-7366
Fax : +61-08-9380-1065
Email : gregr_at_ee.uwa.edu.au
Received on Tue Apr 18 2000 - 02:01:42 NZST