TechBytes » CentOS

Build-Essentials in CentOS?

Asim Zeeshan — Fri, 28 May 2010 17:43:21 +0000

If you are like me, you may be doing this to install essential build libraries to compile something from source

# wrong method
yum install build-essential

Build essential is a Ubuntu / Debian package. On CentOS, you need to do this

yum groupinstall "Development Tools"

Warning: This will install all development tools approx 49 packages closing to 65MB

Linode is Blazzing Fast

Asim Zeeshan — Thu, 27 May 2010 16:24:52 +0000

I asked my client to buy a Linode for some testing purposes and I tried it for the first time. I must say, Linode is blazzing fast. Downloads are touching 8M/sec and speed, performance is as if its running on a VM on my local system.

Update: Now its been almost a month running Linode and I strongly recommend this VPS company.
Update 2: If you plan to signup for LINODE, use my referral link, it will give you the same price but it will help me a lil http://www.linode.com/?r=587d6a71720a4606811a5710431462642c56bc21

Good bye CentOS! Hello Ubuntu

Asim Zeeshan — Fri, 14 May 2010 20:01:00 +0000

Its been about almost more then two years since I have been playing with CentOS on many different platforms etc. Its very stable but on the other hand, PHP/MySQL updates are very hard to get and still PHP is 5.1.6. I tried EPEL repo and it updated PHP to 5.3.1 but still there were conflicts with stuff and many core packages.

So, I thought why not move to Ubuntu since it has just announced 10.04LTS (Long Term Support) in April 2010. Folks at iWeb were really nice to do a reinstall without any charges and also process a memory upgrade request at an amazing 50% discount.

Ubuntu 10.04 LTS

Apache 2 version is 2.2.14
PHP version is 5.3.2
MySQL version is 5.1.41-3ubuntu12
SVN (Subversion) version is 1.6.6

As a comparison CentOS 5.4 has the following versions

Apache 2 version is 2.2.3
PHP version is 5.1.6
MySQL version is 5.0.77
SVN (Subversion) version is 1.4.2

So if you are a PHP developer looking to deploy a Linux flavour on your new box, choose Ubuntu

Bought a new VPS from QuickWeb

Asim Zeeshan — Fri, 07 May 2010 22:09:19 +0000

I just secured a nice deal on QuickWeb.co.nz‘s Texas data center. Thanks to lowendbox for the info on this special coupon. Plan to use it to test new stuff before putting it on my two other production servers (with iWeb.com).

Fixing Pear ‘unsupported protocal’ error

Asim Zeeshan — Tue, 12 Jan 2010 07:00:58 +0000

Are you getting the following error while updating any package in pear?

pear.php.net is using a unsupported protocal – This should never happen.

I got this error right after I upgraded PHP from 5.2 to 5.9 (using CentOS-Testing repo). To resolve this situation, do this.

rm -fr /usr/share/pear/.channels

and then do this

pear update-channels

It should now give you the following output

Updating channel "doc.php.net"
Update of Channel "doc.php.net" succeeded
Updating channel "pear.php.net"
Update of Channel "pear.php.net" succeeded
Updating channel "pecl.php.net"
Update of Channel "pecl.php.net" succeeded

That’s it, your issue is resolved.

To update or not to update?

Asim Zeeshan — Fri, 08 Jan 2010 19:44:50 +0000

All my technical life, I knew and followed this simple rule

New updates to any application or component are meant to improve and fix the bugs present in it. Downloading new updates ensures that you system is up-to-update, has fixes to all those bugs you have been getting annoyed with and more stable.

Unfortunately not every IT department thinks that, especially the one I am facing at work. According to them, the new updates should only be applied IF and only IF they offer some new functionality (duhh!). Hello! what happened to the bug-fixes that are promised with these updates?

Anyway, my Linux box tells me that I have the following updates available but some nut-head thinks its a waste of precious bandwidth

Here is my question, would you update your operating system on a regular basis or would you prefer not to? and WHY?

CentOS yum update missing dependency error

Asim Zeeshan — Fri, 07 Aug 2009 12:13:47 +0000

If you are using

yum update

on CentOS and getting the following errors

Missing Dependency: /usr/lib/python2.4 is needed by package libxml2-python-2.6.26-2.1.2.7.i386 (installed)
gamin-python-0.1.7-8.el5.i386 from installed has depsolving problems
Missing Dependency: /usr/lib/python2.4 is needed by package gamin-python-0.1.7-8.el5.i386 (installed)
Error: Missing Dependency: /usr/lib/python2.4 is needed by package libxml2-python-2.6.26-2.1.2.7.i386 (installed)
Error: Missing Dependency: /usr/lib/python2.4 is needed by package gamin-python-0.1.7-8.el5.i386 (installed)

Don’t panic, the solution is simple … just run the following command

yum clean all

Then do

yum update

Installing PHP 5.2.6 on CentOS box

Asim Zeeshan — Fri, 10 Jul 2009 10:15:03 +0000

If you want to install PHP 5.2.x instead of the PHP 5.1.6 offered with default CentOSPlus repo. Please consider installing the utterramblings repo. Setting up this repo is a breeze … just follow these steps

nano -w /etc/yum.repos.d/utterramblings.repo

(I prefer nano as I mentioned earlier in my posts but you can use vi or any other editor that you like)

Then paste the following code in the editor

[utterramblings]
name=Jason's Utter Ramblings Repo
baseurl=http://www.jasonlitka.com/media/EL$releasever/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka

Hit Ctrl+X and it will prompt you to save this file, you need to confirm this with punching Y

Now comes the last step, type the following and everything will be updated

yum update

Enjoy the latest packages

Note: PHP 5.3.0 is still not available in stable repos because the Zend Optimizer is still in Beta for that particular version.

How to Install Apache, PHP and MySQL on CentOS

Asim Zeeshan — Thu, 02 Jul 2009 04:47:33 +0000

I have seen people installing Apache, PHP and MySQL from source code on a production server. You should NEVER, NEVER, NEVER install these packages from source on an RPM or DEB based Linux distributions. Did I say “NEVER” enough times to make your realize that it is not a good practice?

Installing from source is bad idea; there are many reasons for this but the major one is that you will be spending a lot of time keeping the system updated. If you love installing from source then I would suggest using a different distribution e.g. Gentoo.

You can build from source if the package is not available in yum but still, try to use “yum” (or “apt-get” on Ubuntu) because it will save a lot of your time when upgrading your packages.

So here is the procedure to Install Apache, PHP and MySQL on a CentOS box.

First of all edit the following file using “vi” or any other editor you prefer (I prefer nano)

nano /etc/yum.repos.d/CentOS-Base.repo

Find the line under [centosplus] that reads something like this

enabled = 0

Change it to

enabled = 1

Then do

yum install httpd php mysql-server php-mysql php-gd

This will install Apache, PHP, MySQL and many other common packages

All you need now is to start Apache (httpd) and MySQL (mysqld)

/etc/init.d/httpd start
/etc/init.d/mysqld start

Wow, that was easy, so you got Apache, PHP and MySQL running on your system but still needs to be configured to auto-run on server boot (or reboot). Just punch in the following command and it will be done for both Apache and MySQL (you don’t need to do this for PHP since it is already bind to Apache)

/sbin/chkconfig httpd --level 345 on
/sbin/chkconfig mysqld --level 345 on

345 are basically run level 3, 4 and 5. If you want to study more about Run Levels please consult this article.

That’s it, these simple steps will give install Apache, PHP, MySQL and all the common packages that you will require. Most importantly, you can update these packages with just

yum update

(You may try this command right now but it will not work since you already got all the updated stuff installed)

Updating your system is a breeze now

Note 1: Please change the password for “root” user in MySQL.

Note 2: Your “DocumentRoot” is /var/www/html.

Update: Added instructions to auto-start Apache and MySQL when system starts / restarts.

How to Install Webmin in CentOS

Asim Zeeshan — Wed, 01 Jul 2009 09:20:03 +0000

Update: A newer version of this article is available at http://www.centosblog.com/2012/01/16/how-to-install-webmin-on-centos/

Earlier, I posted a how-to to Install Webmin on Ubuntu, now im going through the tutorial again but this time for CentOS.

Install dependancies before we proceed to install webmin

yum -y install perl-Net-SSLeay

Download the latest version of webmin

wget http://downloads.sourceforge.net/project/webadmin/webmin/1.500/webmin-1.500-1.noarch.rpm?use_mirror=ignum

Once it is downloaded, install the RPM using the following command

rpm -i webmin-1.500-1.noarch.rpm

No more steps required. Its installed
Go to your browser and access the control panel with valid ssh credentials