aio_max_ops(5)aio_max_ops(5)NAMEaio_max_ops - maximum number of POSIX async I/O operations that can be
queued at any time
The minimum value allowed is The maximum value allowed is The value is
further constrained in that it must be greater than or equal to
Specify a positive integer value.
This parameter places a limit on the system resources that can be con‐
sumed if large numbers of POSIX asynchronous I/O operations are queued
on the system at the same time. This parameter limits the ability of
competing processes to overwhelm the system with large numbers of asyn‐
chronous I/O operations and the memory they require.
Each enqueued asynchronous operation requires allocation of system mem‐
ory for its internal control structure, thus making this limit neces‐
sary. In addition to the system-wide limit, there is a per-process
limit that is controlled using the argument to and calls.
limits the number of operations that can be contained in a single call
from a given process, and the value of must be sufficient to meet the
reasonable needs of all processes that are making simultaneous or
nearly simultaneous calls without jeopardizing overall system balance.
Who Is Expected to Change This Tunable?
System administrators that run applications requiring heavy usage of
POSIX AIO to file systems.
Restrictions on Changing
This tunable is dynamic (tuning will take effect immediately on the
What Other Tunables Should Be Changed at the Same Time as This One?
The value assigned to must be greater than or equal to
All HP-UX kernel tunable parameters are release specific. This parame‐
ter may be removed or have its meaning changed in future releases of
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
was developed by HP.
SEE ALSOkctune(1M), sam(1M), gettune(2), settune(2), getrlimit(2), setr‐
limit(2), aio(5), aio_listio_max(5).
Tunable Kernel Parameters aio_max_ops(5)