Starting with Solaris 2.4, a kernel workaround to limit
NFS readdir requests to 1024 bytes was disabled by default.
This breaks interoperability with buggy old NFS implementations
(such as SunOS 3.2, Ultrix and NeXT)
There are two workarounds. The first one works and is:
mount all filesystems from such servers with rsize=1024.
The second one, which requires a patch for bugid #1193696
(101945-29 or later for SPARC, 101946-24 or later for x86)
Edit /etc/system and add:
set nfs:nfs_shrinkreaddir = 1