This will be a simple step by step tutorial to help beginners catch up with ASTERISK - an open source tool for voice communication. It is a software installation of PBX connecting even the PSTN and VOIP networks. Originally developed for Linux, Asterisk now runs on a variety of operating systems including Solaris, Windows and MacOS. Environment setup (more…)

Migrating SSL certificates: CPanel, WHM Possible Scenarios i) Server load balancing ii) Moving web sites between servers Find where the SSL certificates, private keys are installed in the old server and gzip the certs $ tar -zxcf /tmp/crt.tar.gz /etc/ssl/certs $ tar -zxcf /tmp/priv.tar.gz /etc/ssl/private In the new server, extract the certificates and keys to its respective folder location. Edit httpd.conf file and add the following lines SSLEngine on SSLCertificateFile /etc/ssl/certs/example.com.crt SSLCertificateKeyFile /etc/ssl/private/example.com.key SSLCACertificateFile /etc/ssl/certs/example.com.cabundle CustomLog /usr/local/apache/domlogs/exampleuser-ssl_log combined Sample virtual host configuration setting

<VirtualHost xxx.xxx.xxx.xxx:443>
    ServerName subdomain.example.com
    ServerAlias www.subdomain.example.com
    DocumentRoot /home/emaple/public_html
    ScriptAlias /cgi-bin/ /home/example/public_html/cgi-bin/
    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/example.com.crt
    SSLCertificateKeyFile /etc/ssl/private/example.com.key        
   SSLCACertificateFile /etc/ssl/certs/example.com.cabundle    
  CustomLog /usr/local/apache/domlogs/exampleuser-ssl_log combined
    SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown
    <Directory "/home/example.com/public_html/cgi-bin">
        SSLOptions +StdEnvVars
    </Directory>

    # To customize this VirtualHost use an include file at the following location
    # Include "/usr/local/apache/conf/userdata/ssl/2/exampleuser/example.com/*.conf"
</VirtualHost>

Restart apache $ /etc/init.d/httpd restart (or) $ /sbin/service httpd restart Note: Once moving the SSL certificates to the new server, you can also use WHM or CPanel to configure the certs.

Check for the existence of the file sshd_config (/etc/ssh/sshd_config). Before editing the file check that path settings for sftp-server $ locate sftp-server /usr/libexec/openssh/sftp-server Check for the existence of following line in sshd_config Subsystem sftp /usr/libexec/openssh/sftp-server (more…)

To display messages from the log $ cat /var/log/messages | more To show users who are logged in to the system $ who To show the list of users who have logged in last $ last To show the list of all reboots $ last reboot To print the content of the last login log from /var/log/lastlog $ lastlog

When moving mysql database from one server to another or, to test that the data backup works as expected we need to import mysql dump file in the testing environment. Create the database (test-database) in the testing environment and identify the location of the .gz or .sql file. If the mysql dump was a .gz file, you need to gunzip to uncompress the file by typing $ gunzip mysqldump.sql.gz This will uncompress the .gz file and will just store mysqldump.sql in the same location. (more…)

Tar (tape archive) does not compress files. They are used for grouping all files in a folder so that it can be transferred across locations. In order to compress the files, you need to use zip, gzip or bzip2 utilities. gzip, bzip2 are file compression utilities and gunzip, bunzip2 are file uncompression utilities. bzip2 compresses files to a smaller size compared to gzip, but it takes longer to compress the files. Bzip2 uses Burrows-Wheeler block sorting text compression algorithm (with Huffman coding) and gzip uses Lempel-Ziv coding. so, a file compressed with one utility cannot be uncompressed with the other utility. (more…)