Dear managers,
We have recently installed gigabit ethernet cards in a pair of XP-1000's
and connected them through a gigabit switch. One machine is running
tru64 4.0E and the other has Tru64 5.0A. Disks are cross-mounted between
them using NFS. I observe the following:
Copying data from a remote disk to a local disk, i.e. reading from an
NFS-mounted disk, is practically as fast as copying from one local disk
to another.
Copying data from a local disk to a remote disk, i.e. writing to an
NFS-mounted disk, is MUCH slower (a factor of 5 to 10 times slower).
FTP transfer between the two computers is fast in both directions.
I have tried:
Increasing the number of threads for nfsd and nfsiod - helped some.
Using TCP or UDP - both have the same problem.
Using version 2 or 3 NFS - makes little difference.
Increasing rsize and wsize options in the mount - system won't let them
go above 8K.
Increasing kernel parameters tcp_sendspace, tcp_recvspace,
udp_sendspace, udp_recvspace - doesn't make any noticeable difference.
Any suggestions what else to tweak to get writing speed comparable with
reading?
Thanks much,
Marian Szebenyi
MacCHESS, Cornell University
dms35_at_cornell.edu
Received on Thu May 24 2001 - 14:37:34 NZST