AIX Installation in a Partitioned Environment

Hints and Tips

This chapter provides hints and tips to help you when working with AIX in a partitioned environment.

Naming Your Operating System Host Name

Each partition, including the Full System Partition, must have a unique host name that can be resolved. Host names cannot be reused between the Full System Partition and the logical partitions.

If the host name of the partition must be changed, before changing the host name of the partition, do the following:

If your system's level of AIX is earlier than the 5100-02 maintenance package level, skip this step and go to step 2.
```
/usr/sbin/rsct/bin/runact -c IBM.ManagementServer SetRTASPollingInterval Seconds=0
```
Run the following command:
```
/usr/sbin/rsct/bin/lsrsrc IBM.ManagementServer Hostname
```
If the partition is managed by multiple HMCs, multiple entries might exist, because each HMC has its own entry. The output will be similar to the following:
```
  resource 1:
           Hostname       = "hmc1.mydomain.mycompany.com"
```
For each entry, remove the resource using the host name shown. For example, run the following command:
```
/usr/sbin/rsct/bin/rmrsrc -s 'Hostname = "hmc1.mydomain.mycompany.com"' IBM.ManagementServer
```
You can verify that all entries have been removed by running Step 2 again.
Run the following command:
```
/usr/sbin/rsct/bin/rmcctrl -z
```
Change the host name of the partition.
After the host name has been changed, run the following command:
```
/usr/sbin/rsct/bin/rmcctrl -A
```
For information on updating the partition information on the HMC, see the IBM IBM Hardware Management Console for pSeries Installation and Operations Guide, order number SA38-0590.

Network Adapter Communication Between Partitions and the HMC

After a partition has been started, it uses the network adapter to communicate with the HMC. Both the HMC and the partition must be configured so they can use the network adapters to communicate with each other. The partition must be configured to identify the HMC (or HMCs) on the network. It is recommended that the network be configured using a Domain Name Service (DNS) server.

You can use either fully qualified host names or short host names to identify partitions and HMCs. However, it is recommended that each partition and HMC be identified using a fully qualified host name, as this identification ensures unique naming of all the partitions and the HMC in the network. Fully qualified host names cannot be more than 100 bytes in length.

The HMC and partitions can also be configured using a short host name, where the domain name is not defined. This is typically done in a private or test network. If the HMC is defined using a short host name, you must perform extra network configuration steps to ensure correct communications between the partitions and the HMC. If you use short host names rather than fully qualified host names, make sure that the short host names are unique and that the mappings to IP addresses are properly specified.

The search order between the local /etc/hosts file and the DNS can be specified using the /etc/netsvc.conf file or /etc/irs.conf file.

The following examples illustrate the scenarios supported:

If you are using DNS and your partition and the HMC are using fully qualified host names, then no additional network configuration is required.
If you are using DNS and your partition is using a short host name, such as partition_1 and the HMC is also using a short host name, such as hmc123, both must be added to the local /etc/hosts file, as shown in the following:
```
  root@partition_1
-> cat /etc/hosts

127.0.0.1 	loopback localhost	

9.3.3.151	partition_1
9.3.3.152	hmc123
```
If you are not using DNS and your partition is using a fully qualified host name, such as partition_1.mydomain.mycompany.com, and the HMC is also using a fully qualified host name, such as hmc123.mydomain.mycompany.com, both must be added to the local /etc/hosts file, as shown in the following:
```
  root@partition_1.mydomain.mycompany.com
-> cat /etc/hosts

127.0.0.1 	loopback localhost	

9.3.3.151 	partition_1.mydomain.mycompany.com
9.3.3.152	hmc123.mydomain.mycompany.com
```
If you are not using DNS and your partition is using a short host name, such as partition_1 and the HMC is also using a short host name, such as hmc123, both must be be added to the local /etc/hosts file, as shown in the following:
```
  root@partition_1
-> cat /etc/hosts

127.0.0.1 	loopback localhost	

9.3.3.151	partition_1
9.3.3.152	hmc123
```
Your HMC is using a short host name, such as hmc123, and you would like to use both a fully qualified host name and a short host name for the HMC. In order for your partition to correctly communicate with the HMC, you must specify the short host name before the fully qualified host name in the partition's /etc/hosts file, as shown in the following:
```
  root@partition_1.mydomain.mycompany.com
-> cat /etc/hosts

127.0.0.1 	loopback localhost

9.3.3.151	partition_1.mydomain.mycompany.com
9.3.3.152	hmc123 hmc123.mydomain.mycompany.com
```

Shutting Down a Partition

This section provides information about how to shut down a partition by using the HMC and by using AIX.

Using AIX to Shut Down a Partition

When a partition is up, it is in the Running state. To use AIX to shut down a partition, do the following:

To restart AIX, on the AIX command prompt, type shutdown -Fr.
The partition eventually changes to the Starting state, and the operator panel values display, which indicates AIX is now rebooting.
When the reboot is issued within AIX, the partition will boot according to the contents of the bootlist. To check the order of the boot devices, type bootlist -m normal -o
To shut down AIX, on the AIX command prompt, type shutdown -F.

The partition will eventually change to the Ready state. You have now shut down AIX and its partition.

To start AIX, on the HMC, select Activate. When you select Activate, the HMC uses the boot mode selection in the partition profile.

Using the HMC Interface to Shut Down a Partition

To use the HMC to shut down a partition, do the following:

Select the partition you want to shut down.
Right-click on the partition to open the menu.
Select Operating System Reset.
Select Hard Reset. This action sends a halt signal indicating which instance of AIX is to be shut down. If a vterm window was open while the hard reset was done, the vterm window remains open. The partition will then be in the Ready state.

To activate the partition, select the partition and press the right mouse button. Select Activate. When you select Activate, the HMC uses the boot mode selection in the partition profile.

Closing a vterm window does not shut down a partition. However, closing the window logs you off that session and kills any processes that you are running from that vterm window.