If you need to be able to retrieve thousands of lines back in the ssh applet by using the scrollbar in the ssh window, there are three places where you can set this value in the PAM Client:
The first one is a global setting set by the administrators for all the users and devices.
The second one overrides the global definition for a particular device.
The third one overrides the global settings for a particular user and can be modified by the own user without any admin privilege.