NFS and slow links

[Dominick Samperi]

We have observed a significant performance hit when links are done
over the network (via NFS). At first I thought this was due to the
fact that we are linking against several large libraries. So I
copied the libraries to a local disk, and was surprised to find
that it made very little difference. Further investigation
revealed that what made all of the difference was whether or
not the user's home directory was local or NFS-mounted. More
precisely, the performance hit resulted from the need to write
the output executable file (about 10Megs) to an NFS-mounted
directory. Modifying the makefile so that the output executable
file is written to a local ("cache") partition removed the
performance hit.

Surely this must be a problem that others have encountered. Does
anybody have a better solution? We are using SunOS 4.1.

It appears that NFS works well when one is making many small
requests, say, to fetch object files from a library over the
network, or to include header files from NFS-mounted directories.
But there is a significant hit when NFS is used to copy a large
file (or create a large executable file). One observation that
I cannot explain is the fact that large executables that are
located in remote (NFS-mounted) directories seem to start up
quickly (faster than a straight copy). Any ideas?

Thanks for any feedback on this.


-- 
Dominick Samperi -- Citicorp
dsamperi at Citicorp.COM
uunet!ccorp!dsamperi