nswapdev(5)nswapdev(5)NAMEnswapdev - maximum number of devices that can be enabled for swap
VALUES
Default
Allowed values
DESCRIPTION
Swap devices are managed in a table for easier indexing in the kernel.
sets the kernel variable responsible for the upper limit on this table,
and thus the upper limit to devices which can be used for swap.
Who is Expected to Change This Tunable?
Anyone.
Restrictions on Changing
Changes to this tunable take effect at the next reboot.
When Should the Value of This Tunable Be Raised?
If another swap device is added to the system which would increase the
number of devices above and returns to the caller (see the swapon(2)
manpage).
What Are the Side Effects of Raising the Value?
More devices can be added to the system, and the kernel will need a
little more memory for the table. A small performance side effect of
the kernel having to scan more devices to check for a duplicate device
during is also true, but realistically negligible.
When Should the Value of This Tunable Be Lowered?
Only if you are sure the system will never go over a certain number of
swap devices, and you wish to lower this tunable to save a small amount
of kernel memory and kernel performance during operations.
What Are the Side Effects of Lowering the Value?
No side effects other than the primary and presumably desired new limi‐
tation on the number of swap devices.
What Other Tunable Values Should Be Changed at the Same Time?
None.
WARNINGS
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.
Tunable Kernel Parameters nswapdev(5)