nproc

Description

The nproc parameter specifies the number of entries in the system process (proc) table. Each running process requires an in-core proc structure. Thus nproc is the maximum number of processes that can exist in the system at any given time.

The default value of nproc is based on the amount of memory on your system. To find the currently auto-configured value of nproc, use the systune(1M) command.

The nproc parameter is defined in /var/sysgen/mtune.

Value

Default: 0 (Automatically configured if set to 0)

Range: 30-10000

When to Change

Increase this parameter if you see an overflow in the sar -v output for the proc -sz ov column or you receive the operating system message:

no more processes

This means that the total number of processes in the system has reached the current setting. If processes are prevented from forking (being created), increase this parameter. A related parameter is maxup.

Notes

If a process can't fork, make sure that this is system-wide, and not just a user ID problem (see the maxup parameter).

If nproc is too small, processes that try to fork receive the operating system error:

EAGAIN: No more processes

The shell also returns a message:

fork failed: too many processes

If a system daemon such as sched, vhand, init, or bdflush can't allocate a process table entry, the system halts and displays:

No process slots