Resolution:
The GridServer Manager may fail in Linux and Solaris because the maximum file descripter count has been exceeded. For example, Solaris 8 has a default max file descriptor count of 1024. This can be eclipsed when you have your Resin threadcount at 500 with 800 or more Engines. This is generally caused by heavy use of GridCache, because global cache regions are stored in files on the Broker's filesystem.

To avoid this, set the limit to something higher. In Solaris, you can use the command ulimit -n 8192 to raise the count to 8192 on a per-process basis, or edit /etc/system to raise this globally.

In Linux,you should edit the /proc/sys/fs/file-max file, although this should only be necessary in 2.4 kernels (2.6 dynamically adjusts this based on usage).

GridServer Manager fails, max file descripter count exceeded