maxfiles_lim(5)maxfiles_lim(5)NAMEmaxfiles_lim - hard maximum number of file descriptors per process
VALUES
Failsafe
Default
Allowed values
The minimum value allowed is 32. The maximum value allowed is 1048576,
or 1M. The value is further constrained in that it must be equal or
greater than the soft limit,
Specify a positive integer value.
Recommended values
At runtime, a warning will be issued if the tunable is set to a value
greater than 409600, or 400K. This is beyond the tested limit.
At runtime, a warning will be issued if the value is not a multiple of
the file descriptor chunk (multiple of 8) size. This is not a serious
warning, just an information message for the administrator.
DESCRIPTION
specifies the system hard limit for the number of file descriptors that
a process is allowed to have for open files at any given time. It is
possible for a nonsuperuser process to increase its soft limit up to
this hard limit.
Who Is Expected to Change This Tunable?
Anyone expecting to run applications using large numbers of file
descriptors.
Restrictions on Changing
The tunable is dynamic (tuning will take effect immediately on the run‐
ning system).
Dynamic changes affect all existing processes in the system except:
· Processes that have more file descriptors allocated than allowed by
the new limit,
· Processes that have specifically set their limits through a call to
or
When Should the Value of This Tunable Be Raised?
The tunable should be increased when large numbers of file descriptors
are expected to be open by several processes.
What are the Side Effects of Raising the Value?
There is no immediate effect of raising the value of However, doing so
allows any process to allocate more file descriptors, potentially con‐
suming more system memory.
When Should the Value of This Tunable Be Lowered?
The value should be lowered to limit the number of open file descrip‐
tors per process on a system and reduce system memory consumption.
What are the Side Effects of Lowering the Value?
Lowering the value of bounds memory consumption due to file descriptors
for processes that are not already over the new limit.
What Other Tunable Values Should Be Changed at the Same Time?
The value assigned to must be less than or equal to the value of
Kernel checks during tunable setting ensure these restrictions.
WARNINGS
For values greater than 65535, compatibility for the obsolescent will
be affected. For correct operation, all applications must use instead
of If the system still has applications using setting to 65535 or less
will maintain compatibility, unless the process being queried has used
to change its maximum limit of open files to a value greater than
65535.
All HP-UX kernel tunable parameters are release specific. This parame‐
ter may be removed or have its meaning changed in future releases of
HP-UX.
Installation of optional kernel software, from HP or other vendors, may
cause changes to tunable parameter values. After installation, some
tunable parameters may no longer be at the default or recommended val‐
ues. For information about the effects of installation on tunable val‐
ues, consult the documentation for the kernel software being installed.
For information about optional kernel software that was factory
installed on your system, see at
AUTHOR
was developed by HP.
SEE ALSOkctune(1M), sam(1M), setrlimit(2), gettune(2), settune(2), pstat(2),
ulimit(2), maxfiles(5).
Tunable Kernel Parameters maxfiles_lim(5)
