Verify Installation Prerequisites

Verify prerequisites before running the STA installer. The installation will fail if any of these prerequisites are not met.

The STA installation assumes 64‐bit Linux has been installed with the Linux RPM packages specified in Install Required Linux Packages. If a required package is not installed, the STA installation will display an error message and not allow you to continue until the package is installed. See Requirements for STA for a complete list of installation requirements.

Before choosing to permanently remove or replace existing software, back up files as needed.
On the STA server, open a terminal session. Log in as the Oracle user.
Verify that STA is not installed on the server. For example:
```
$ ls /etc/init.d/sta*
ls: cannot access /etc/init.d/sta*: No such file or directory
$ ls /usr/bin/STA
ls: cannot access /usr/bin/STA: No such file or directory
```
If STA is already installed, you must deinstall it and then install the new version of STA and then upgrade the database. See Upgrade to STA 2.4.0 for details.

Verify that MySQL is not installed on the STA server. For example:

$ ls /etc/init.d/mysql*
ls: cannot access /etc/init.d/mysql*: No such file or directory
$ ls /usr/bin/mysql*
ls: cannot access /usr/bin/mysql*: No such file or directory

If MySQL is already installed, you must deinstall it before you can install STA.

Verify that the /tmp directory has at least 4 GB of free space. For example:

$ df -H /tmp
Filesystem             Size   Used  Avail Use% Mounted on /dev/mapper/vg_tbivb03-lv_root        53G    35G    16G  70% /

Verify that the Oracle storage home location has at least 11 GB of free space. This is the default STA and WebLogic installer working location. For example:
```
$ df -H /Oracle
Filesystem             Size   Used  Avail Use% Mounted on /dev/mapper/vg_tbivb03-STA_OracleVol  34G   3.8G    29G  12% /Oracle
```
If the directory does not have enough space, you can optionally specify a different working directory when you start the STA installer. See "STA installer working location" for details.

Verify SELinux is disabled.

$ sestatus
SELinux status:         disabled

Verify the iptables firewall service is running. Depending on your site configuration, this step may require system root privileges.
Linux 6:
```
$ sudo service iptables status
```
Linux 7:
```
$ systemctl status iptables
```
Stop and deconfigure SNMP services.
To avoid network port collisions and other issues, the STA server must not run other SNMP services. The STA installer will quit in the following situations:
- The snmpd and snmptrapd daemon services are running,
- UDP ports 161 (SNMP) and 162 (SNMPTRAP) are not available.
Perform the following steps as required to stop the SNMP services:
1. Display the current status of the SNMP snmpd and snmptrapd services.
  Linux 6:
```
$ service snmpd status 
$ service snmptrapd status 
```
  Linux 7:
```
$ systemctl status snmpd 
$ systemctl status snmptrapd 
```
2. If necessary, stop the SNMP services immediately.
  Linux 6:
```
$ service snmpd stop 
$ service snmptrapd stop
```
  Linux 7:
```
$ systemctl stop snmpd 
$ systemctl stop snmptrapd
```
  If you receive a "FAILED" error, the services may already be stopped.
3. Disable the SNMP services in the Linux services configuration file so they do not start automatically when Linux reboots. Depending on your site configuration, this step may require system root privileges.
  Linux 6:
```
$ sudo chkconfig snmpd off 
$ sudo chkconfig snmptrapd off 
```
  Linux 7:
```
$ systemctl disable snmpd 
$ systemctl disable snmptrapd 
```
Review and verify the applicable mode-specific requirements, as follows:
- For the installation wizard, see Installation Wizard Display Requirements.
- For the silent-mode installer, see Silent-mode Requirements.