msgseg(5) File Formats Manual msgseg(5)NAME
msgseg - number of System V IPC message segments in the system (OBSOLETE)
DESCRIPTION
The tunable is obsolete and has been removed.
This tunable specified the total number of "segments" of system-wide shared memory message storage space which is shared among all IPC mes-
sage queues. This tunable is replaced by the tunable msgmbs(5) (The maximum (in megabytes) kernel memory to be used for messages waiting
to be received.)
For more information about System V message queues, refer to the section of the mesg(5) manpage.
WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter has been obsoleted for HP-UX 11i Version 3 and forward.
AUTHOR
was developed by AT&T.
SEE ALSO msgsnd(2), mesg(5), msgmbs(5), msgmap(5), msgmax(5), msgmnb(5), msgmni(5), msgssz(5), msgtql(5).
OBSOLETE Tunable Kernel Parameters msgseg(5)
Check Out this Related Man Page
msgmbs(5) File Formats Manual msgmbs(5)NAME
msgmbs - maximum number of megabytes for all System V IPC message queues
VALUES
Default
Failsafe
Allowed Values
DESCRIPTION
The tunable specifies the maximum allowable total combined size, in megabytes, of all System V IPC messages in the system at any one time.
If a system call attempts to exceed the limit imposed by it will block (or return if was specified) until a caller of decreases the number
of queued message bytes sufficiently such that the new message, along with other messages still on the queue, will fit within the limit.
For more information about System V message queues, refer to the section of the mesg(5) manpage.
Who Is Expected to Change This Tunable?
Anyone.
Restrictions on Changing
This tunable is dynamic. Changes to to this tunable take effect immediately. Changes affect subsequent operations.
When Should the Value of This Tunable Be Raised?
Raise this tunable if applications have a need to store more data on a system.
What are the Side Effects of Raising the Value?
Raising this value increases the total message data which may be queued at any point in time. This can result in having to block less fre-
quently.
Since message queue headers are stored in kernel memory, that memory is unavailable for use by other system services.
When Should the Value of This Tunable Be Lowered?
Lower this tunable when applications have no need to store large amounts of data on a single queue.
What are the Side Effects of Lowering the Value?
Lowering the tunable value has no effect on any active messages, even if the new tunable value is less than the total number of message
bytes currently enqueued. However, no new messages may be queued until the total number of bytes falls below the setting of
What Other Tunable Values Should Be Changed at the Same Time?
All the System V message queue tunables are interrelated and should be treated as independent variables. The set must be evaluated as a
system to ensure the tunables reflect the application requirements. The message tunables include and tunables.
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.
System resource limits (such as, memory) may limit the number and/or total size of queued messages. These system limits may be encountered
before the limit values of the msgtql and msgmbs tunables.
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 AT&T.
SEE ALSO msgrcv(2), msgsnd(2), mesg(5), msgmni(5), msgtql(5), msgmnb(5).
Tunable Kernel Parameters msgmbs(5)