Solaris Tunable Parameters Reference Manual

rlim_fd_max

Description

"Hard" limit on file descriptors that a single process might have open. To override this limit requires superuser privilege.

Data Type

Signed integer

Default

1024

Range

1 to MAXINT

Units

File descriptors

Dynamic?

No

Validation

None

When to Change

When the maximum number of open files for a process is not enough. Note that other limitations in system facilities can mean that a larger number of file descriptors is not as useful as it might be:

  • A 32-bit program using standard I/O is limited to 256 file descriptors. A 64-bit program using standard I/O can use up to 2 billion descriptors.

  • select(3C) is by default limited to 1024 descriptors per fd_set. Starting with the Solaris 7 release, 32-bit application code can be recompiled with a larger fd_set size (less than or equal to 65,536). A 64-bit application sees an fd_set size of 65,536, which cannot be changed.

An alternative to changing this on a system wide basis is to use the plimit(1) command. If a parent process has its limits changed by plimit, all children inherit the increased limit. This is useful for daemons such as inetd.

Commitment Level

Unstable