Comment 39 for bug 1006446

We also see this problem in our network.

Our setup with NO problems:
SERVER1 NFS server running Ubuntu 11.10 (Kernel 3.0.0-12-server) (2 x Quadcore Xeon 2.4GHz 16GB Ram)
SERVER2 Webserver running Ubuntu 8.04 (Kernel 2.6.27.7) (Dualcore Xeon 3.00GHz 2GB Ram)
SERVER3 Webserver running Ubuntu 12.04 (Kernel 3.2.0-29-generic) (2 x Quadcode Xeon 2.5GHz 8GB Ram)
SERVER4 Webserver running Ubuntu 11.10 (Kernel 3.0.0-12-server) (2 x Quadcore Xeon 2.4GHz 16GB Ram)

All webserver get there content from the NFS server.

We updated the 8.04 server to 12.04 (Kernel 3.2.0-23-generic-pae) and the problems started.
We did apache benchmark tests, when using SERVER4: no problems. Running the same test on SERVER 2 or 3 the load of both SERVER 2 & 3 go sky high (loads of 200+ seen)

I watched nfsiostat on SERVER 2 when running the apache benchmark on SERVER 3 and the read/write where 0.00 but the op/s where somewehe around 1200.00