There are prerequisites to installing the Controller on a Linux OS.

Install libaio on Linux

Before it begins Controller installation, the installer checks whether the target Linux system has the libaio library installed. This library provides for asynchronous I/O operations on the system.

**Red Hat and CentOS**

Use the following command to install the libaio package:

yum install libaio

**Ubuntu**

Use the following command to install the libaio package:

sudo apt-get install libaio1

**Fedora**

Install the RPM for the libaio package from the Fedora website.

**Debian**

For Debian, you can use a package manager such as APT to install libaio (as described for the Ubuntu instructions above).

**Check the Limits for Number of File Descriptors**

As the root user, execute following command:

ulimit -S -n

If this value is less than 65535, change it to 65535 either in the limits.conf file.

On Fedora as well as Ubuntu (and probably other modern Linux distributions) using /etc/security/limits.conf is the preferred method. You should put the ulimit command in /etc/profile only if the /etc/security/limits.conf does not exist.

**Configure Limits Per User in limits.conf file**

1.Open the limits.conf file for edit:

/etc/security/limits.conf

2.Add the following lines:

hard nofile 65535
soft nofile 65535

Where ''login_user'' is the username of the Linux user who runs the Controller, such as ''appdynamics''.

3.Enable these limits by editing:

/etc/pam.d/common-session

4.Add the line:

session required pam_limits.so

When you log in again as the ''appdynamics'' user, the limits apply.

**Configure Swappiness on Linux**

The default value is usually 60. For better AppDynamics performance, the recommended value is 0 (zero).

To configure swappiness

1.Check the current value for swappiness.

/sbin/sysctl -a | grep swappiness

As recommended, if the value is something other than 0, continue setting the value.

2.Set the swappiness parameter to zero.

echo 0 > /proc/sys/vm/swappiness

3.Edit the /etc/sysctl.conf file and add following line:

vm.swappiness = 0