NFS and File Over Write Performance

[Derek Buttineau]

Just curious if anyone has run into this before.  We are testing an HP  
DL380 G5 Storage Server.  The odd thing I'm experiencing is when over  
writing a file on the NFS share with the FreeBSD NFS client my  
transfer speed is about 1/3 of what it is if I'm creating a new file  
on the share.  This is all over a 1Gb link and I'm using clpbar to  
monitor speeds on the copy.

 From my tests, initial file creation gets me about 89MB/s, while  
overwriting gets me about 25MB/s

The same test using RHEL4 as the client gives a consistent 79MB/s for  
creation and overwrite.

Seems very strange and I've tested from FreeBSD 6.2, 6.3 and 7.0, all  
with the same results.

Any thoughts?

Thanks,

Derek