This article explains the features of the HP-UX 11i v3
swapoff command incorporated on the September 2008 release. This command
provides the ability to remove swap devices without rebooting the system. This
feature is enabled by the command and an enhanced system call swapctl(2):
"The HP-UX Swapoff command, swapoff(1M), is a Software
Pack product and is delivered as an optional product on all Operating
Environments. For more information about Software Pack, see ?Software Pack
(Optional HP-UX 11i v3 Core Enhancements)".
The swapctl(2) system call has been enhanced through patches
delivered in the FEATURE11i patch bundle.
Contents
1 Abstract
2 Procedure
3 Usage
4 Example
5 Reference
6 Authors
Procedure
This enhancement to the swapctl(2) is automatically
delivered through a patch in the September 2008 FEATURE11i bundle. To add the
swapon installation of the Swapoff Enhancement bundle is required. This bundle
is available on current DVD media and for download at the Software Depot
website:
HP-UX Swapoff
1. Verified that the HP-UX 11i v3 has installed the
FEATURE11i bundle.
# swlist -l bundle | grep -e HPUX11i -e FEATURE11i
FEATURE11i B.11.31.0809.326a Feature Enablement
Patches for HP-UX 11i v3, September 2008
HPUX11i-VSE-OE B.11.31.0803 HP-UX Virtual Server Operating Environment
2. Install the swapoff bundle.
# swinstall -s
/var/tmp/swapoff_B.11.31.0809.02_HP-UX_B.11.31_IA_PA.depot \*
======= 11/08/08
22:41:59 MST BEGIN swinstall SESSION
(non-interactive) (jobid=zx6000-0015)
* Session started
for user "root@zx6000".
* Beginning
Selection
* Target
connection succeeded for "zx6000:/".
*
"zx6000:/var/tmp/swapoff_B.11.31.0809.02_HP-UX_B.11.31_IA_PA.depot":
Cannot open the
logfile on this target or source.
Possibly
the media is
read-only or there is a permission problem.
Check the
daemon logfile and "/var/tmp/swagent.log" on this
host for more
information.
* Source:
/var/tmp/swapoff_B.11.31.0809.02_HP-UX_B.11.31_IA_PA.depot
* Targets: zx6000:/
* Software
selections:
swapoff,r=B.11.31.0809.02,a=HP-UX_B.11.31_IA/PA,v=HP
Swapoff.SWAPOFF,r=B.11.31.0809.02,a=HP-UX_B.11.31_IA/PA,v=HP,fr=B.11.31.0809.02,fa=HP-UX_B.11.31_IA
Swapoff.SWAPOFF-ENG-MAN,r=B.11.31.0809.02,a=HP-UX_B.11.31_IA/PA,v=HP,fr=B.11.31.0809.02,fa=HP-UX_B.11.31_IA
* Selection succeeded.
* Beginning
Analysis and Execution
* Session
selections have been saved in the file
"/.sw/sessions/swinstall.last".
* The analysis
phase succeeded for "zx6000:/".
* The execution
phase succeeded for "zx6000:/".
* Analysis and
Execution succeeded.
NOTE: More
information may be found in the agent logfile using the
command
"swjob -a log zx6000-0015 @ zx6000:/".
======= 11/08/08
22:42:26 MST END swinstall SESSION
(non-interactive)
(jobid=zx6000-0015)
Usage
Complete details of the usage of the swapoff command is
described on it's manpage.
# man swapoff
swapoff(1M)
swapoff(1M)
NAME
swapoff - online
disabling of swap device
SYNOPSIS
/usr/sbin/swapoff device ...
DESCRIPTION
The swapoff
command disables swapping on the specified swap device(s)
for the current
boot. (NOTE: the term swap refers to an
obsolete
implementation
of virtual memory; HP-UX actually implements virtual
memory by way of
paging rather than swapping. This
command and others
retain names
derived from swap for historical reasons.)
Notes
+ The swapoff command will not remove entry
from /etc/fstab for the
device. The /etc/fstab file needs
to be modified to remove the
device
entries.
+ The swapoff command is guaranteed to
disable the swap devices for
the current
boot only when the devices were enabled for swapping
through
swapon (see swapon(1M).
+ A swap device will not be disabled if the
current available
system swap
space without the device is not sufficient for the
system to
operate.
RETURN VALUE
swapoff returns
one of the following values:
0 Successful completion.
>0 Error condition occurred.
EXAMPLE
The following
example disable paging on block device
/usr/sbin/swapoff /dev/dsk/c10t0d0
AUTHOR
swapoff was
developed by HP.
SEE ALSO
swapinfo(1M),
swapon(1M), swapctl(2), fstab(4).
Hewlett-Packard
Company - 1 - HP-UX 11i Version 3: May 2008
Example
The following example demonstrates the usage of the swapoff
to remove swap devices without rebooting the system, an LVM logical volume is
used as swap device for the demonstration.
# swapinfo -tam
Mb Mb
Mb PCT START/
Mb
TYPE AVAIL
USED FREE USED
LIMIT RESERVE PRI NAME
dev 12288 0
12288 0% 0
- 1 /dev/vg00/lvol2
reserve - 391
-391
memory 1938 628
1310 32%
total 14226 1019
13207 7% -
0 -
# lvcreate -L 1024 -n swap2 /dev/vg01
Logical volume "/dev/vg01/swap2" has been
successfully created with
character device "/dev/vg01/rswap2".
Logical volume "/dev/vg01/swap2" has been
successfully extended.
Volume Group configuration for /dev/vg01 has been saved in
/etc/lvmconf/vg01.conf
# swapon -p 1 /dev/vg01/swap2
# swapinfo -tam
Mb Mb
Mb PCT START/
Mb
TYPE AVAIL USED
FREE USED LIMIT RESERVE PRI
NAME
dev 12288 0
12288 0% 0
- 1 /dev/vg00/lvol2
dev 1024 0
1024 0% 0
- 1 /dev/vg01/swap2
reserve - 391
-391
memory 1938 628
1310 32%
total 15250 1019
14231 7%
- 0 -
# swapoff /dev/vg01/swap2
# swapinfo -tam
Mb Mb
Mb PCT START/
Mb
TYPE AVAIL USED
FREE USED LIMIT RESERVE PRI
NAME
dev 12288 0
12288 0% 0
- 1 /dev/vg00/lvol2
reserve - 391
-391
memory 1938 628
1310 32%
total 14226 1019
13207 7% -
0 -
# lvremove /dev/vg01/swap2
The logical volume "/dev/vg01/swap2" is not empty;
do you really want to delete the logical volume (y/n) : y
Logical volume "/dev/vg01/swap2" has been
successfully removed.
Volume Group configuration for /dev/vg01 has been saved in
/etc/lvmconf/vg01.conf
Thank you for Reading,
