Oracle® Solaris 11.2 Tunable Parameters Reference Manual

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Updated: December 2014
 
 

maxusers

Description

Originally, maxusers defined the number of logged in users the system could support. When a kernel was generated, various tables were sized based on this setting. Current Oracle Solaris releases do much of its sizing based on the amount of memory on the system. Thus, much of the past use of maxusers has changed. A number of subsystems that are still 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 look-up cache (DNLC)

Data Type

Signed integer

Default

Lesser of the amount of memory in MB or 2048, and the greater of that value and nCPUs x 8

Range

1 to the greater of 2048 or nCPUs x 8, based on the size of physical memory, if not set in the /etc/system file

1 to the greater of 4096 or the nCPUs x 8, if set in the /etc/system file

Units

Users

Dynamic?

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

Validation

If the value is greater than the maximum allowed, it is reset to the maximum. A message to that effect is displayed.

When to Change

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

out of processes

You might also change this parameter when the default number of processes is too high, as in these situations:

  • Database servers that have a lot of memory and relatively few running processes can save system memory when the default value of maxusers is reduced.

  • If file servers have a lot of memory and few running processes, you might reduce this value. However, you should explicitly set the size of the DNLC. See ncsize.

Commitment Level

Unstable