nfs_getpages: error 70 vm_fault: pager read error

[Cedric Tabary]

I have 6 dell 1850, dual xeon, 2G ram, no HTT
4 are running RELENG_6 from Mon Jan  9
2 are running RELENG_5_4 from Tue Oct  4

They are used as web servers apache 1.3
web pages are on a NetAPP F760 with nfs options :
rw,soft,intr,nfsv3,mntudp,-r=8192,-w=8192,noatime,acregmin=30

the dmesg is full of  :

pid 34397 (httpd), uid 100: exited on signal 11
pid 80101 (httpd), uid 100: exited on signal 6
nfs_getpages: error 70
vm_fault: pager read error, pid 78999 (httpd)
pid 78999 (httpd), uid 100: exited on signal 11
pid 15738 (httpd), uid 100: exited on signal 11
pid 14910 (httpd), uid 100: exited on signal 11
nfs_getpages: error 70
vm_fault: pager read error, pid 15981 (httpd)
pid 15981 (httpd), uid 100: exited on signal 11

pid 84481 (httpd), uid 100: exited on signal 11
nfs_getpages: error 60
vm_fault: pager read error, pid 54468 (httpd)
pid 46271 (httpd), uid 100: exited on signal 11

pid 54916 (httpd), uid 100: exited on signal 11
pid 28818 (httpd), uid 100: exited on signal 11
nfs_getpages: error 5
vm_fault: pager read error, pid 93494 (httpd)
pid 2734 (httpd), uid 100: exited on signal 11


Do you have an idea of what happens ?

Thanks

Cédric