Updating environment settings for a partitioned Db2 installation (AIX)

This task describes the environment settings that you need to update on each computer that will participate in your partitioned database system.

Procedure

To update AIX® environment settings:

Log on to the computer as a user with root user authority.
Set the AIX maxuproc (maximum number of processes per user) device attribute to 4096 by entering the following command:
```
  chdev -l sys0 -a maxuproc='4096'
```
Note: A bosboot/reboot may be required to switch to the 64-bit kernel if a different image is being run.
Set the TCP/IP network parameters on all the workstations that are participating in your partitioned database system to the following values. These values are the minimum values for these parameters. If any of the network-related parameters are already set to a higher value, do not change it.
```
   thewall       = 65536
   sb_max        = 1310720
   rfc1323       = 1
   tcp_sendspace = 221184
   tcp_recvspace = 221184
   udp_sendspace = 65536
   udp_recvspace = 65536
   ipqmaxlen     = 250
   somaxconn     = 1024
```
To list the current settings of all network-related parameters, enter the following command:
```
   no -a | more
```
To set a parameter, enter the follow command:
```
   no -o parameter_name=value
```
where:
- parameter_name represents the parameter you want to set.
- value represents the value that you want to set for this parameter.
For example, to set the tcp_sendspace parameter to 221184, enter the following command:
```
   no -o tcp_sendspace=221184
```
If you are using a high speed interconnect, you must set the spoolsize and rpoolsize for css0 to the following values:
```
   spoolsize     16777216
   rpoolsize     16777216
```
To list the current settings of these parameters, enter the following command:
```
   lsattr -l css0 -E 
```
To set these parameters, enter the following commands:
```
   /usr/lpp/ssp/css/chgcss -l css0 -a spoolsize=16777216
   /usr/lpp/ssp/css/chgcss -l css0 -a rpoolsize=16777216
```
If you are not using the /tftpboot/tuning.cst file to tune your system, you can use the DB2DIR/misc/rc.local.sample sample script file, where DB2DIR is path where the Db2 database product has been installed, to update the network-related parameters after installation. To update the network-related parameters using the sample script file after installation, perform the following steps:
1. Copy this script file to the /etc directory and make it executable by root by entering the following commands:
```
   cp /usr/opt/db2_09_01/misc/rc.local.sample /etc/rc.local
   chown root:sys /etc/rc.local
   chmod 744 /etc/rc.local
```
2. Review the /etc/rc.local file and update it if necessary.
3. Add an entry to the /etc/inittab file so that the /etc/rc.local script is executed whenever the machine is rebooted.
  You can use the mkitab command to add an entry to the /etc/inittab file.
  To add this entry, enter the following command:
```
   mkitab "rclocal:2:wait:/etc/rc.local > /dev/console 2>&1"
```
4. Ensure that /etc/rc.nfs entry is included in the /etc/inittab file by entering the following command:
```
   lsitab rcnfs
```
5. Update the network parameters without rebooting your system by entering the following command:
```
   /etc/rc.local
```
Ensure that you have enough paging space for a partitioned installation of Db2 Enterprise Server Edition to run.
If you do not have sufficient paging space, the operating system will kill the process that is using the most virtual memory (this is likely to be one of the Db2 processes).
To check for available paging space, enter the following command:
```
   lsps -a
```
This command will return output similar to the following:
```
Page Space  Physical Volume  Volume Group  Size  %Used  Active  Auto  Type
paging00    hdisk1           rootvg        60MB     19     yes   yes    lv
hd6         hdisk0           rootvg        60MB     21     yes   yes    lv
hd6         hdisk2           rootvg        64MB     21     yes   yes    lv
```
The paging space available should be equal to twice the amount of physical memory installed on your computer.
If you are creating a small to intermediate size partitioned database system, the number of network file system daemons (NFSDs) on the instance-owning computer should be close to:
```
   # of biod on a computer × # of computers in the instance
```
Ideally, you should run 10 biod processes on every computer. According to the preceding formula, on a four computer system with 10 biod processes, you use 40 NFSDs.

If you are installing a larger system, you can have up to 120 NFSDs on the computer.

For additional information about NFS, refer to your NFS documentation.