LCD and X DisplaySize

Posted on: Sat, 10/15/2005 - 05:00 By: Huahai

Under Linux, have you ever felt that stuff on your brand new LCD display looked blurry, especially with small font sizes, the words start to look fuzzy after a while? Chances are that you did not set the LCD with its optimal resolution. There is an easy fix:
1. Measure the actually size of your LCD display area in millimeters (mm). Use a ruler. For example, my small X31 screen measures 240mm (width) by 180mm (height ).
2. Now check the values you have in your X configuration
xdpyinfo | grep dimensions

Dual Head with Xorg on Thinkpad X31

Posted on: Sat, 10/15/2005 - 05:00 By: Huahai

My Thinkpad X31 got a small 12.1 inch screen, so I decide to increase the screen real estate by adding an extra monitor. The idea is that the LCD and the CRT monitor will display different part of the same desktop. This dual head solution is sometimes called 'Xinerama' in X terminology.

Centralized authentication with LDAP + NFS + Samba (Part II: NFS)

Posted on: Mon, 01/17/2005 - 05:00 By: Huahai

NFS (Network File System) is an old Unix technology that enables a machine to mount a remote file system. This is desirable for centralized authentication, as the user can access the same home directory no matter which machine he uses.

Server

Install NFS server:
apt-get install nfs-kernel-server

Edit /etc/exports, put in lines such as

/home *.dept.school.edu(rw,no_subtree_check)

to export directories to allow machines on local network have access to /home and its subdirectories.

Start the server:

/etc/init.d/nfs-kernel-server start

If you have a personal firewall running on the machine, you will need to configure it so NFS traffic can be served from this machine. On MEPIS Linux, go to Guarddog->Protocol->Local->Network File System - Sun Microsystems, and check the box, apply; For client, goto the Internet zone, instead of Local zone, check the same box. Since NFS is highly vulunrable for exploitation, you should make sure your whole subnetwork is behind a firewall.

Client

We would like to automatically mount the NFS volume when a user is trying to access it. am-utils, an automounter, will do this. Get and install it:
apt-get install am-utils
*use NIS: no

Centralized authentication with LDAP + NFS + Samba (Part I: LDAP)

Posted on: Mon, 01/17/2005 - 05:00 By: Huahai

Ok, what is centralized authentication? Why bother? Well, if each person in your home or organization uses her/his own computer only, no need for this. However, if you or your organization have a bunch of machines and people need to login to different machines at different times, you've got a problem. Do you want to setup an account for each person on each machine? What about people's files? People would like to have access to their files no matter where they login. For this kind of environment, centralized authentication is the way to go.

I am setting up a centralized authentication environment for a small work group, it consists of 7 or so Debian Linux boxes, 2 Sun Solaris boxes, and 5 Windows 2k/XP machines. Since the budget is tight, I will use all open source solution for this setup, namely, OpenLDAP, NFS and Samba.

The actual setup proved to be quite easy, but took us a few days to figure it out, mostly due to the scant documentation available. I hope this series of posts can help alleviate this problem. The first installment deals with seting up LDAP server and client on Debian Linux machines. Most of the steps assume you have root privilige.

LDAP Server

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