extending the max number of open files.

[William Quayle]

billq at cbnewsc.att.com (William Quayle) writes:
>The max number of open files is compiled into the kernel, and is
>determined using the "MAXUSERS" parameter in the configuration file...

Well, the system maintains a set of structures describing open files, but
it refers to all open files on the system. The size of the set is
determined at build time by an arcane formula (in /usr/sys/conf/param.c in
SunOS 3.x) based on MAXUSERS from the conf file. If you need to increase
it muck around with the specific formula for it in param.c. Just
arbitrarily bumping up MAXUSERS can get you into other messes.

The problem that most people run into and complain about is the limit on
open files per process. In 3.3 it's 30 and in 4.x it's 64 and is called
"NOFILE" (found in /usr/include/sys/param.h). There are several grungy
things in the kernel that make changing this unpretty (eg, the way the
descripter is encoded in ioctl parameters passed to the kernel).