AIX - OS Readiness for 11gRac

AIX Os -Prerequsite for 11gr2.


A. System. Parameters.

Maixmum no. of userprocess  -  maxuproc - 16384
No. of arguments    -  ncargs   - 128

-> list the current

# lsattr -E -l sys0 -a maxuproc
# lsattr -E -l sys0 -a ncargs

-> To change to the desired value.

# chdev -l sys0 -a maxuproc=16384
# chdev -l sys0 -a ncargs=128


B. Tune Virtual memory parameters. IBM recommended numbers are:


minperm%=3
maxperm%=90
maxclient%=90
lru_file_repage=0
strict_maxperm=0
strict_maxclient=1
page_steal_method=1
lru_poll_interval=10

Script to change the parameters:-

#!/usr/bin/ksh
vmo -p -o maxperm%=90;
vmo -p -o minperm%=3;
vmo -p -o maxclient%=90;
vmo -p -o lru_file_repage=0;
vmo -r -o page_steal_method=1; (need to reboot to take into effect)
vmo -p -o strict_maxclient=1
vmo -p -o strict_maxperm=0;
vmo -p -o lru_poll_interval=10

C. Do not assign PVIDs (Physical Volume IDs) to disks or volumes that are being used for ASM Diskgroups. PVIDs should be cleared on all nodes from any candidate disks or volumes prior to being added to an ASM  Diskgroup. Once a disk or volume is added to an ASM Diskgroup, PVIDs should never be assigned after the fact, from any node in the cluster, including nodes that are being added to an existing cluster.

CAUTION:  Assigning PVIDs to ASM disks will corrupt the disk header resulting in catastrophic data loss!!

To check

# lspv

hdisk0 0003286f04bc73ee rootvg active
hdisk1 0003286f867d77e1 rootvg active
hdisk2 0003286fb3470dae vg01 active
hdisk3 0003286fb3474190 vg01 active
hdisk4 0003286fb34747d1 vg01 active
hdisk5 0003286fb3474dff vg01 active
hdisk6 0003286fb3475428 vg01 active
hdisk7 0003286fb347607d vg01 active
hdisk8 0003286fb34766f3 vg01 active
hdisk9 0003286fb3476d70 vg01 active
hdisk10 0003286fb34773d5 vg01 active

The second column is the PVID.

To Change

# chdev -l hdiskn -a pv=clear


D. Network Consideration.

Ensure that the network tuning parameters are set in accordance with the following to ensure optimal interconnect performance:

tcp_recvspace = 65536
tcp_sendspace = 65536
udp_sendspace = ((DB_BLOCK_SIZE * DB_MULTIBLOCK_READ_COUNT) + 4 KB) but no lower than 65536
udp_recvspace = 655360 (Minimum recommended value is 10x udp_sendspace, parameter value must be less than sb_max)
rfc1323 = 1
sb_max = 4194304
ipqmaxlen = 512

NOTE: Failure to set the udp_sendspace will result in failure of root.sh for 11.2.0.2 GI installations, see Document 1280234.1.

To check
no -a | fgrep ephemeral
no -a | fgrep tcp
no -a | fgrep udp
no -a | fgrep max

To change
no -p -o tcp_ephemeral_low=9000 -o tcp_ephemeral_high=65500"
no -p -o udp_ephemeral_low=9000 -o udp_ephemeral_high=65500"
no -p -o udp_sendspace=65536 -o udp_recvspace=655360"
no -p -o sb_max=4194304"
no -p -o tcp_sendspace=65536
no -p -o tcp_recvspace=65536


E. Resever lock should not be set on the disks.


To check:-

# lsattr -El hdiskn | grep reserve

To Change:-

# chdev -l hdiskn -a reserve_lock=no

F. Checking the user capabilities.

Ensure that the GI and ORACLE owner account has the CAP_NUMA_ATTACH, CAP_BYPASS_RAC_VMM, and CAP_PROPAGATE capabilities.
This is required per the 11gR2 installation guide and it is also required for all pre-11gR2 installations.
Check and Set example for GRID user is as follows:

To check

# lsuser -f oracle | grep capabilities
# lsuser -f grid   | grep capabilities

To Change

# chuser capabilitie=CAP_NUMA_ATTACH,CAP_BYPASS_RAC_VMM,CAP_PROPAGATE grid
# chuser capabilitie=CAP_NUMA_ATTACH,CAP_BYPASS_RAC_VMM,CAP_PROPAGATE oracle


G. Create a softlink for ssh and scp , because the oui will look for these tools in /usr/bin


ln -s /usr/local/bin/ssh /usr/bin/ssh
ln -s /usr/local/bin/scp /usr/bin/scp

H. Create a softlink for network parameter check tool no

ln -s /usr/sbin/no /etc/no"

I. Checking os version.

# oslevel

# uname -a

J. Checking memory .

-- Ram Size.

# lsattr -E -l sys0 -a realmem

-- Swap memory.

# lsps

Recommended by oralce if RAM is less than 2 gb then swap should be 2 * RAM size, for 2gb -16 gb the swap
should be size of the RAM, and above 16 gb the swap should be 16gb.

K. OS Fileset checking.

# lslpp -L | grep fileset

Need to apply the db one off patch on AIX server.
10190759 : PROCESSES CONSUMING ADDITIONAL MEMORY DUE TO 'USLA HEAP'