Configuring your system for Large Physical Memory
To configure memory above 4GB do the following:
-
Set the following boot parameter in /stand/boot
to enable the detection of memory above 4GB and switch UnixWare
into PAE mode:
ENABLE_4GB_MEM=YES
NOTE:
You must be in PAE mode to use memory above 4GB.
If you want to switch out of PAE mode,
you must reboot with ENABLE_4GB_MEM disabled
(either defined as ``NO'', or not defined).
To effect this change permanently, edit the file /stand/boot
and add this line.
(You can also interrupt the boot process using
the interactive Boot Command Processor (BCP) to
set this parameter temporarily.)
-
If you want to dedicate memory, set the tunable parameter
DEDICATED_MEMORY to the amount of memory required for
PSE SHM, DSHM, or FGA-SHM (in pages).
You can set the parameter using the System Tuner
or the idtune command.
-
Execute idbuild to rebuild the system using the
values just defined.
-
Reboot the system.
For example,
on a system with 3GB of memory, the following sequence
configures 2GB worth of pages as dedicated memory (note that
you do not have to define ENABLE_4GB_MEM in this case):
-
Enter the following commands:
idtune DEDICATED_MEMORY 524288
/etc/conf/bin/idbuild
shutdown
Or, on a system with 8GB of memory, the following sequence
configures 6GB worth of pages as dedicated memory:
-
Define
ENABLE_4GB_MEM=Y
in /stand/boot.
-
Enter the following commands:
idtune DEDICATED_MEMORY 1572864
/etc/conf/bin/idbuild
shutdown
NOTE:
An alternative way to divide memory between ``dedicated''
and ``general purpose'' uses is to define the specific amount of
memory to be reserved for general purpose
use (rather than to define the specific amount of dedicated memory you want):
-
Set the tunable DEDICATED_MEMORY to 16777216 (that is,
64GB, the maximum value it can be set to).
-
Set the tunable GENERAL_MEMORY to the amount of memory you want
to reserve for that purpose (up to 4GB).
This alternative works because the tunable parameter
GENERAL_MEMORY overrides DEDICATED_MEMORY if they conflict.
There is an advantage to using this method
because GENERAL_MEMORY acts as a safety net of
sorts, allowing the system to at least boot and operate with adequate
general memory should a bank of memory fail (not be present).
Next topic:
Configuring swap space for systems with Large Physical Memory
Previous topic:
Managing Large Physical Memory
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 22 April 2004