Patch 101945-17 introduced an bug in the NFS client code that makes
that programs using NFS locking will sometimes go in an
interruptible read. (I.e., you can kill the program that hangs)
Truss will show the program sleeping in read(2) while top
will show it eating CPU. The ksh seems to have this quite
a lot. There's also a lot of network traffic.
Fix: install a patch for bug-id #1198278 on your NFS clients.
(101945-29 or later for SPARC, 101946-24 or later for x86)
Workaround: mount NFS filesystems with "noac", but this costs