[CentOS] DNS problem (on NAT configuration)

Mon Apr 28 16:40:54 UTC 2008
Les Mikesell <lesmikesell at gmail.com>

Patricia Bittencourt wrote:
> Thank you Les, John, for the reply.
> One thing that I noticed is that there are lots of nfs connections in 
> TIME_WAIT. And since I have been facing problems with NFS (ie. taking 
> too much time to cd to a mounting area on client) the problems regarding 
> network appeared.
> The TIME_WAIT connections does not free memory, rigth? Do you believe 
> that NFS might be creating a network congestion? Among NFS optimization 
> possibilities is that one in particular that take more effect to avoid 
> performance problems in your oppinion?

TIME_WAIT states happen when you close a TCP connection which shouldn't 
happen at all on nailed-up mounts.  Do you have the automounter set up 
for short timeouts and something that could be traversing the mount 
points frequently to stir up traffic and connections?  You could switch 
to UDP to avoid the TCP state handshakes and overhead.

   Les Mikesell
    lesmikesell at gmail.com