shmmax(5)							File Formats Manual							 shmmax(5)

NAME

       shmmax - maximum size (in bytes) for a System V shared memory segment

VALUES

   Default
   Allowed values
DESCRIPTION

       Shared  memory is an efficient InterProcess Communications (IPC) mechanism.  One process creates a shared memory segment and attaches it to
       its address space.  Any processes looking to communicate with this process through the shared memory segment, then attach the shared memory
       segment	to  their  corresponding  address spaces as well.  Once attached, a process can read from or write to the segment depending on the
       permissions specified while attaching it.

       This tunable sets the maximum size for such a segment within the system, and is dynamic as of HP-UX 11i.

   Who is Expected to Change This Tunable?
       Anyone.

   Restrictions on Changing
       Changes to this tunable take effect immediately.

   When Should the Value of This Tunable Be Raised?
       should be raised if it is below the maximum and user programs are attempting to segments larger than the current value,	and  receiving	an
       error message.

   What Are the Side Effects of Raising the Value?
       The only effect is that user programs can use to get larger segments.

   When Should the Value of This Tunable Be Lowered?
       If you wish to enforce behavior on the user's code, limiting the maximum size of System V segments.

   What Are the Side Effects of Lowering the Value?
       None.

   What Other Tunable Values Should Be Changed at the Same Time?
       and  should  be	considered  because  enforcing smaller segments may cause the user's code to try to create more segments to accomplish the
       task.

WARNINGS

       All HP-UX kernel tunable parameters are release specific.  This parameter 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 values.  For information about the effects of installation  on  tun-
       able  values,  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 ALSO

       shmem(5), shmmni(5), shmseg(5).

							     Tunable Kernel Parameters							 shmmax(5)