Software Free

Question: Can you give me more information on how to set up MySQL cluster?

Answer: Sure, below are the links to extremely informative Internet resources providing detailed guides on why and how to deploy MySQL cluster.

By the way a cluster in IT field is a group of linked computers, working together so they form a single computing system. The components of a cluster are usually connected to each other via fast local area networks. Clusters are usually deployed to improve performance and/or availability over that provided by a single computer, while typically being much more cost-effective than single computers of comparable speed or availability.

1. http://dev.mysql.com/doc/refman/5.0/en/mysql-cluster.html

Question: How can I block traffic coming from specific operating system in Linux? In other words, how can I block traffic from Windows users on my firewall and allows other people?

Question: How can I get my Linux server rebooted/restarted automatically if it caught a kernel panic?

Answer: As you might know, kernel panic is an action taken by an operating system upon detecting an internal fatal error from which it cannot safely recover; the term is largely specific to Unix and Unix-like systems (it’s a wiki’s description).

Question: How can I disable building of directory index in apache/httpd? In other words, how to prevent users from seeing the contents of published directories?

Answer: Actually you are totally right that you wish to disable this feature. One of the "must do’s" on setting a secure apache web server is to disable directory browsing. Usually apache comes with this feature enabled but its always a good idea to get it disabled unless you really need it.

First of all find where is the main apache’s config file httpd.conf is located. If you use Debian, it should be here: /etc/apache/httpd.conf. Using some file editor like Vim or Nano open this file and find the line that looks as follows:

Options Includes Indexes FollowSymLinks MultiViews

Question: I want to select APT repository server/mirror that is fastest for my location. How can I do it in Debian?

Answer: You can use application named as "netselect-apt" to get new sources.list file with fastest APT mirror. Install this application by command "sudo aptitude install netselect-apt" and run it in accordance with Debian distribution you use (Debian Etch in our example):

sudo netselect-apt -n etch -o /etc/apt/sources.list
sudo apt-get update

The phpMyFAQ Team would like to announce the availability of phpMyFAQ 2.0.7, the “Whit Monday” release. This release adds a Bengali and an Ukraine translation. The Czech translation was updated and we fixed some minor bugs.
[ED can be used with firebird backend]

Question: I want to reset counters in /proc/net/dev (also shown in ifconfig output as RX and TX bytes) and thus I have to unload network interface driver. How to do it?

Answer: There are two commands in Linux CLI coming by default which would help to unload drivers: rmmod and modprobe. First of all it is necessary to find what kernel module controls certain NIC and then unload that module. For example, you have VIA VT6102 (RHINE-II) network card that is recognized by Linux as eth0 and want to disable its driver temporarily. Just execute the following:

"sudo rmmod via-rhine" or "sudo modprobe -r eth0" (or "sudo modprobe -r via-rhine"). You can use command dmesg to determine the name of kernel module you wish to unload.

Question: How can I restrict/allow access to certain service on timely basis with iptables? For example restrict access to SSH between 7:00 pm - 8:00 am on weekdays?

Answer: You are welcome to use iptables patch-o-matic extension (pom or p-o-m) that allows you to match a packet based on its arrival or departure (for locally generated packets) timestamp. The syntax is the following:

iptables RULE -m time --timestart TIME --timestop TIME --days DAYS -j ACTION

Where:

Question: How can I get information about hardware manufacturer, model name, serial number, BIOS information using Linux command line (CLI)?

Answer: You are welcome to use dmidecode which helps to get information about your system’s hardware as described in your system BIOS. That information typically includes system manufacturer, model name, serial number, BIOS version, asset tag as well as a lot of other details depending on the manufacturer.

Static routing is the term used to refer to the manual method used to set up routing. An administrator enters routes into the router using configuration commands. This method has the advantage of being predictable, and simple to set up. It is easy to manage in small networks but does not scale well.

Question: How can I save static routes I set up in my Fedora/RedHat/CentOS Linux after I reboot server?

Answer: In Fedora Linux (or RedHat, CentOS) you can set up static routes for certain network interface (for example eth1) by editing file /etc/sysconfig/network-scripts/route-eth1.

For example, you have to save static route added by the following command: