Nginx: UserAgent based transfer rate limit

January 28th, 2010 by joseph No comments »

In this post we’ll show an example on how to implement transfer rate limitation in Nginx. As this limitation is User agent based, itwould be especially meaningful for a download site, or a mirror site like mirror.centos.org.
» Read more: Nginx: UserAgent based transfer rate limit

Dell PE2950 LCD Message explained

January 22nd, 2010 by joseph No comments »

Dell PowerEdge 2950 control dashboard LCD provides status messages to signify when its physical system is operating well or when needs some attention. The LCD lights blue to indicate a normal operating condition, and lights amber to indicate an error condition.

The LCD scrolls a message that includes a status code followed by descriptive text. The following section lists the LCD status messages that can occur and the probable cause for each message. » Read more: Dell PE2950 LCD Message explained

Query IP whois info in python

January 18th, 2010 by joseph No comments »

This is a simple python script  based on some former rwhois code. It shows us an easy way on how to get detailed information about a specific IP address:

joseph@e54:~$ python ip-whois.py 94.75.214.11
====== whois.arin.net                        

OrgName:    RIPE Network Coordination Centre
OrgID:      RIPE
Address:    P.O. Box 10096 » Read more: Query IP whois info in python

Rename a Vserver step by step

January 6th, 2010 by joseph No comments »

Suppose you made a mistake on the Vserver name when creating it. After finished the installation, you might want to rename your Vserver. This can be accomplished by renaming the config directory and the root for the vserver in question, then modifying some symlinks to match. » Read more: Rename a Vserver step by step

Ways to reset MySQL user password

January 1st, 2010 by joseph No comments »

How can I change user password under MySQL server when I lost my password?
Here’s I’ll show two examples. The first example is about how to change password for normal user using Linux command line option, and the second example is on how to reset MySQL DBA password (By default, this user is called root). » Read more: Ways to reset MySQL user password

Update CentOS 4 to CentOS 5 remotely

December 31st, 2009 by joseph 2 comments »

I just successfully updated my Dell PowerEdge 1850 from CentOS 4.8 to CentOS 5.4, luckily the issues I faced were not so rare. The steps I used are listed below, may it helpful for you as well! Although this post is mainly intended for CentOS it should work on RHEL systems as well.

Before you start, A word of advice i believe most experienced RHEL/CentOS users will show you regarding what you’re thinking:

Upgrade between minor versions (i.e. CentOS 5.2 -> 5.3 -> 5.4, or even 5.0 -> 5.4) YES
Upgrade between major system versions (i.e. CentOS 4.8 to CentOS 5.4) NO » Read more: Update CentOS 4 to CentOS 5 remotely

Failover Firewalls with OpenBSD and CARP

December 30th, 2009 by joseph No comments »

Warning – this post was original created by Jason Dixon some yrs ago, its copyright is fully held by samag.com. I copied it here for a track record, If there’s any issue, please let me know. As the pictures in this post had lost already,  it’s suggested to check its PDF version here.

Firewalls are a required component in commercial and residential computer networks. For many installations, the firewall is a single point of failure between client systems and external resources. It can also become a liability when hardware or applications fail, leaving potential customers unable to reach your servers. » Read more: Failover Firewalls with OpenBSD and CARP

Explained Awk1line and Sed1line

December 13th, 2009 by joseph No comments »

If you have ever been interested in awk and sed Unix commands, then you probably know about the awk1line.txt and sed1line.txt files that are floating around the Internet. Each file contains around 80 idiomatic sed and awk one-liners for performing various text modification tasks. » Read more: Explained Awk1line and Sed1line

Set timezone date and time in Linux

December 13th, 2009 by joseph No comments »

Your computer has two timepieces; a battery-backed one that is always running (a.k.a. the hardware, BIOS, or CMOS clock), and another that is maintained by the operating system currently running, it’s called system clock. This document explains how to set your system clock, your timezone, and other stuff related to how linux does its time-keeping. » Read more: Set timezone date and time in Linux

Cassandra: Structured Key-Value based storage system

December 11th, 2009 by joseph No comments »

Cassandra is an open source distributed database management system. It was initially developed by Facebook for storing very large amounts of data. Jeff Hammerbacher, who led the Facebook Data team at the time, has described Cassandra as a BigTable data model running on a Amazon Dynamo-like infrastructure. » Read more: Cassandra: Structured Key-Value based storage system