Reducing
Default Paging Space in AIX (hd6)
This document describes how to reduce the size of the
default paging space
(hd6). This information applies to AIX Version 4.x.
WARNING: Please do not use this document if the system is
a /usr client,
diskless client, or dataless client.
Procedure to reduce default paging space
Procedure to reduce default paging space AIX version
before 5.1
1. First check if your paging
space is mirrored.
lslv -m hd6
If it is mirrored, then you will need to break the mirror.
For
example:
lslv -m hd6
PV1 PV2
hdisk0 hdisk1
rmlvcopy hd6 1 hdisk1
lslv -m hd6 (Now
it should only show one copy)
PV1
hdisk0
2. Determine how many paging space
logical volumes exist on your system.
Enter:
lsps -a
If there is more than one paging space in rootvg, note
their names
(listed in the Page Space column) and go to Step 3.
If there is just one paging space in rootvg (it will be be
named
hd6), continue with Step 2.
3. Check how many free physical
partitions (PPs) are available. Enter:
lsvg -p rootvg
Create a paging space to use temporarily with the
following command.
X is a number between 1 and the total number of free PPs
shown in the
lsvg output.
mkps -s X -a rootvg
Run lsps -a again and note the name of the new paging
space (probably
paging00).
4. Change the characteristics of the
default paging space (hd6) so that
it is not active at the next reboot.
Enter:
chps -a n hd6
5. Edit the file. Enter:
"/sbin/rc.boot"
Change the line swapon /dev/hd6 to swapon /dev/pagingXX,
where XX is
the number of one of the paging spaces found in
Step 1, or the number
of the new paging space created in Step 2.
6. Determine which disk is the boot
disk with the lslv command. The boot
disk will be shown in the PV1 column
of the lslv output.
lslv -m hd5
WARNING: Do not proceed further if the system is a /usr
client,
diskless client, or dataless client.
7. Now, run the bosboot command,
using the hdisk# determined in Step 5.
Enter:
bosboot -a -d /dev/hdisk#
8. The system needs to be rebooted in
order to inactivate the hd6 paging
space. Enter:
shutdown -Fr
9. The default dump device is set to
hd6. hd6 cannot be removed while it
is the dump device. Check the dump
device. Enter:
sysdumpdev -l
If the primary or secondary dump device is set to hd6 then
reset the
pointer. Enter:
sysdumpdev -P -p /dev/sysdumpnull
10. Because certain scripts are currently hard-coded to activate
/dev/hd6, it is recommended to create
the new paging space under the
same name. Remove hd6 and create a
new hd6 of smaller size, with the
following commands (<PS size in
logical partitions> is the number of
LPs to allocate to hd6):
rmps hd6
mklv -y hd6 -t paging rootvg <PS size in logical
partitions>
11. Edit the file. Enter:
"/sbin/rc.boot"
Change the swapon line back to swapon
/dev/hd6.
12. Run:
lsps -a
to see if hd6 is marked to be automatically swapped on at
boot time.
This is determined by a y under the auto column for hd6.
If an n is
under the auto column, run:
chps -a y hd6
to change the characteristics of the
default paging space.
13. Run the bosboot command, using the hdisk# determined in
Step 5.
bosboot -a -d /dev/hdisk#
14. If a temporary paging space was not created, this is the end
of
the procedure. Otherwise, continue
with the following steps.
15. Change the characteristics of the temporary paging space
(which
is assumed to be paging00 in these
steps), so that it is not active
at the next reboot. Enter:
chps -a n paging00
16. The system needs to be rebooted in order to inactivate the
temporary paging space. Enter:
shutdown -Fr
17. Remove the temporary paging space. Enter:
rmps paging00
18. If the dump device was changed in Step 8 then reset the
dump
pointer. Enter:
sysdumpdev -P -p /dev/hd6
19. If you broke the mirror to hd6 in Step 1, then replace
the
mirrored copy.
For example:
mklvcopy hd6 2 hdisk1
lslv -m hd6
PV1 PV2
hdisk0 hdisk1
Procedure to reduce default
paging space AIX version 5.1 or above
1. First check if your paging
space is mirrored.
lslv -m hd6
If it is mirrored, then you will need to break the mirror.
For
example:
lslv -m hd6
PV1 PV2
hdisk0 hdisk1
rmlvcopy hd6 1 hdisk1
lslv -m hd6 (Now
it should only show one copy)
PV1
hdisk0
2. Check if you have APAR
IY19145 installed.
instfix -ik
IY19145
If this APAR is not installed, the system may crash when
reducing
paging space with AIX 5.1.
3. Reduce default paging
space hd6.
chps -d <number of logical
partitions> hd6
4. If you broke the mirror to hd6 in
Step 1, then replace the mirrored
copy.
For example:
mklvcopy hd6 2 hdisk1
lslv -m hd6
PV1 PV2
hdisk0 hdisk1
