How to Resolved -bash: crontab: command not found error

Symptoms:
When i try to crontab command on my CentOS 5 server, it will return this error message:

    [root@server ~]# crontab -l
    -bash: crontab: command not found
    or
    [root@server ~]# crontab -e
    -bash: crontab: command not found
    

Findings:
crontab was not installed on this server.

Solution :
Just run yum install to install the crontab on your CentOS 5 server.

    [root@server ~]# yum install vixie-cron
    

How to View the Source Code on Mozila Firefox 7.0.1

Symptoms:
Since i upgraded my mozila firefox to version 7.0.1, i no longer have the option to View/source code. This view source code feature is useful when I need to see the HTML code.

Solution:
View Page Source is now available from the Firefox menu. It appears to have been moved to Tools -> Web Developer -> Page Source
view source

The keyboard shortcut is Ctrl + U

How to Fix MySQL Database error : Can’t create database ‘newdbname’ (errno: 28)

Symptoms:
When i run the command to create new database on mysql, it was returned with below error message. How to fix this?

    mysql> CREATE DATABASE newdbname;
    ERROR 1006 (HY000): Can't create database 'newdbname' (errno: 28)
    

Findings and Solutions :
This error means that your mysql server does not have enough free space. You need to check the file system size and please remove unwanted software(s) or installers or files. What we suggest is please try to remove the files in /tmp first before you proceed to remove other files of software’s. Or maybe you can ask the system administrator to increase the partition size.

    [root@server ~]# cd /tmp
    [root@server ~]# rm -rf *
    

Restart mysql server:

    [root@server ~]# service mysqld restart
    

Please re-run the below command:

    mysql> CREATE DATABASE newdbname;
    Query OK, 1 row affected (0.00 sec)
    

How to Install Serendipity blog on CentOS 5.5

Serendipity is a PHP blog application which gives the user an easy way to maintain an online diary, weblog or even a complete homepage. It is very simple application and very easy to install. In this post, i will guide you on how to install the serendipity on CentOS 5.5 with apache, mysql and php installed.

Steps :
1. Download the package.

    [root@server www]# pwd
    /var/www
    [root@server www]# wget http://cdnetworks-kr-2.dl.sourceforge.net/project/php-blog/serendipity/1.5.5/serendipity-1.5.5.tar.gz
    

2. Extract the tar file

    [root@server www]# tar xzvf serendipity-1.5.5.tar.gz
    

3. Create the database as below

    mysql> CREATE DATABASE serdb;
    mysql> CREATE USER 'seruser'@'localhost' IDENTIFIED BY 'serpassword';
    mysql> GRANT ALL PRIVILEGES ON serdb.* to seruser@localhost ;
    mysql> SHOW GRANTS FOR 'seruser'@'localhost';
    

Database type : MySQL
Database host : localhost
Database user : seruser
Database password : serpassword
Database name : serdb

4. Run the installation wizard as below.
http://yourdomain.com/serendipity/index.php.
Serendipity

5. Proceed to the installation wizard until below page.
Serendipity

How to Check and Verify The Site That You Want You Visit Using SiteAdvisor

There is an easy way to verify the website that you always visit or want to visit is safe or not using SiteAdvisor.The SiteAdvisor technology is free, easy to install and even easier to use. And it doesn’t collect any personally identifiable information. This method require installation of the SiteAdvisor software. With SiteAdvisor software installed, your browser will look a little different than before. We add small site rating icons to your search results as well as a browser button and optional search box. Together, these alert you to potentially risky sites and help you find safer alternatives. However you also can verify the website without installing any SiteAdvisor software. you just need to browse this URL, www.siteadvisor.com. If website is linked to a bad websites and one user reported the site as a phishing or scam, SiteAdvisor will marked that site as Caution of Warning.

If you want to verify other websites in the future, I would recommend that you use this site advisor:

1. Go to http://www.siteadvisor.com
2. Enter the site that you want to visit and click view report now.
siteadvisor
3. If the target website haven’t tested yet, then it will go for the verification procedure and will return this message.

“This site has been queued for testing. Please come back soon for automated results.”