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biosdecode is a command line utility to parses the BIOS memory and prints information about all structures (or entry points) it knows of. The DMI table doesn’t only describe what the system is currently made of, it also can report the possible evolutions such as the fastest supported CPU or the maximal amount of memory supported. In this tip you will learn about decoding BIOS data (dumping a computer’s DMI ) and getting all information about computer hardware without rebooting the server.

Adobe Acrobat is a commercial tool for manipulating PDF files. Earlier I was using CUPs - printing system, to export PDF files. I’ve also tried out gv for the same purpose. However, I needed complete editing of pdf documents. My search ended with PDFedit software, which is free and open source editor for manipulating PDF documents. The software available in both GUI and CLI (commandline) interface.

Your Debian / Ubuntu Linux box security depends upon access to system services (one of many aspects). For example, you may need to provide a web server (Apache service) to serve web pages. However, if you do not need use a service, you should always turn off all unused services to avoid exploits.

Traditionally, Debian provided various tools to manage services. There are various methods for managing access to system services:
a) /etc/init.d/service
b) rcconf
c) update-rc.d etc

Under Red hat and Centos Linux you can use chkconfig command (ntsysv command) to configure Sys V style init script links. There is also service command to stop / start / restart services.

You can find the memory used by a program (process) by looking into /proc directory or using standard command such as ps or top. However, you must calculate all memory usage by hand i.e. add Shared Memory + mapped file + total virtual memory size of the process + Resident Set Size + non-swapped physical memory used by process.

So how do you find the memory used by a process or program under Linux?

If a kernel panic occurs for the first time you have to no choice but to reboot Linux box manually.

If you want the server to get rebooted automatically after kernel hit by a pain error message, try adding panic=N to /etc/sysctl.conf file.

It specify kernel behavior on panic. By default, the kernel will not reboot after a panic, but this option will cause a kernel reboot after N seconds.

Internet SCSI (iSCSI) is a network protocol that allows you to use of the SCSI protocol over TCP/IP networks. It is good alternative to Fibre Channel-based SANs. You can easily manage, mount and format iSCSI Volume under Linux. It allows access to SAN storage over Ethernet. Open-iSCSI project is a high-performance, transport independent, multi-platform implementation of iSCSI. Open-iSCSI is partitioned into user and kernel parts.

DNS server can be attacked using various techniques such as:
[a] DNS spoofing

[b] Cache poisoning

[c] Registration hijacking

One of the simplest ways to defend is limit zone transfers between nameservers by defining ACL. I see many admin allows BIND to transfer zones in bulk outside their network or organization. There is no need to do this. Remember you don't have to make an attacker's life easier.

Restricting zone transfers with IP addresses in BIND DNS Server

The problem of cooling the computer is not new. The more powerful and faster computers become, the "hotter" they get. Coolers inside computer cases, video card and power supply units are quite common nowadays. However, hard disk has no additional means to cool them. Most hard disk manufacture recommends 35-40°C working temperature for a hard drive. Once it crossed the limit safety of your data and hard disk becomes critical. Computer hard drive is the main storage media for your data.

This article explains how to monitor hard disk temperature and prevent the loss of data under Linux using automated scripts.

Sometime by mistakes all file permissions get changed and you need to restore file permission. For example a shell script or some sort of corruption could change the permissions for packages (installed files), it may be necessary to reset them.

For example a long time ago my shell script run chmod and chown commands on /usr and changed the permission. Luckily rpm command can reset package permission. Sun Solaris pkg command and IBM can also reset permissions.

Malware is software designed to infiltrate or damage a computer system without the owner's informed consent. It is a portmanteau of the words "malicious" and
"software". The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code.

Setting up a malware blacklist in Postix MTA is quite easy. The Malware Block List is a free, automated and user contributed system for checking URLs for the presence of Viruses, Trojans, Worms, or any other software considered Malware