Solaris Tunable Parameters Reference Manual



Originally, maxusers defined the number of logged in users the system could support. Various tables were sized based on this setting when a kernel was generated. Now, the Solaris release does much of its sizing based on the amount of memory on the system, so much of the past use of maxusers has changed. There are still a number of subsystems that are derived from maxusers:

  • The maximum number of processes on the system

  • The number of quota structures held in the system

  • The size of the directory name lookup cache (DNLC)

Data Type

Signed integer


Lesser of the amount of memory in Mbytes and 2048


1 to 2048, based on physical memory if not set in the /etc/system file.

1 to 4096, if set in the /etc/system file.




No. After computation of dependent variables is done, maxusers is never referenced again.



When to Change

When the default number of user processes derived by the system is too low. This situation is seen by the following message that displays on the system console:

out of processes

When the default number of processes is too high:

  • Database servers that have a lot of memory and relatively few running processes, can save system memory by reducing the default value of maxusers.

  • File servers that have a lot of memory and few running processes can reduce this value, but should explicitly set the size of the DNLC. (See ncsize.)

  • Compute servers that have a lot of memory and few running processes can reduce this value.

Commitment Level


Change History

For information, see maxusers (Solaris 7 Release).