Verify the Required SDM_localhost Entry is in the Hosts File

You must verify that the required SDM_localhost entry is in the /etc/hosts file that is used for internal server communication within a cluster, or for any OCSDM server(s) in your environment that do not rely on a domain name server (DNS).

Note:

The IP address that is used for the SDM_localhost entry on each OCSDM cluster member must be registered on the network Domain Name Server (DNS). If this entry is absent on the DNS server, DNS lookup timeouts occur, which can cause database problems.

Enter the ifconfig command to view the Ethernet 0 (eth0) IP address on the OCSDM server.

[my_linux_system]$ ifconfig

eth0      Link encap:Ethernet  HWaddr 00:21:F6:69:00:33
          inet addr:10.138.222.189  Bcast:10.138.223.255  Mask:255.255.252.0
          inet6 addr: fe80::221:f6ff:fe69:33/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:31991154 errors:0 dropped:0 overruns:0 frame:0
          TX packets:10798060 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2842355697 (2.6 GiB)  TX bytes:26025276531 (24.2 GiB)
          Interrupt:163

View the /etc/hosts file to verify that there is a SDM_localhost entry and that the IP address of this entry matches the eth0 interface.
The following example has the correct eth0 interface (shown in the previous example) and SDM_localhost entry:
```
[my_linux_system]$ Vi /etc/hosts
10.138.222.189 acme189 SDM_localhost
```
If the /etc/hosts file does not include the eth0 IP address and SDM_localhost entries, enter them in the /etc/hosts file using the following format:

Note:
The order in which this entry appears in the hosts file does not matter.
For example:
```
<eth0 IP address> <optional hostname(s)> SDM_localhost
```
Note:
SDM_localhost does not support IPv6 link-local addresses.
If you fail to add the SDM_localhost entry in the hosts file, the following message appears during the OCSDM setup installation process:
```
Setup encountered an error and cannot continue!
INVALID_SERVICE_CONFIGURATION: /etc/hosts file is not configured correctly. There should be one entry for SDM_localhost. Please refer to the installation documents for proper syntax.
```
Restart the network service to initialize the changes that you made to the hosts file.
```
$ service network restart
```