LinuxHostingSupport

Generally, a sub-domain is not accessed using the www prefix i.e. you can access subdomain.domain.tld but not www.subdomain.domain.tld by default.

Solution:

To make a subdomain work with ‘www’ prefix on a Plesk server, you have to add a ServerAlias entry in the vhost configuration of the sub-domain and add an A record from Plesk.

Steps:

1. Create a vhost.conf file for the sub-domain

# cd /var/www/vhosts/domain.tld/subdomains/<sub-domain>/conf

# nano vhost.conf

and add a ServerAlias entry

ServerAlias www.subdomain.domain.tld

2. Add an ‘A’ record for the ‘www’ prefix of the sub-domain from
     Plesk -> Domains -> <domain.tld> -> DNS Settings -> Add Record

www.subdomain.domain.tld A 1.1.1.1

3. To apply the ServerAlias changes, run the websrvmng utility

# /usr/local/psa/admin/bin/websrvmng -a

4. Restart the webserver

# service httpd restart

Replace the subdomain/domain name and the 1.1.1.1 IP with the actual values.

The ‘uname‘ command is use to determine certain system information in all the Linux/Unix flavours like CentOS, Ubuntu, Debian, Fedora, FreeBSD etc. With specific ‘uname’ options, you can display all the details of the current working kernel on the server.

To display the working kernel name, version, date and time, system architecture type etc, use:

# uname -a

Linux server.domain.tld 2.6.18-164.11.1.el5 #1

SMP Wed Jan 20 07:39:04 EST 2010 i686 i686 i386 GNU/Linux

To print only the kernel version along with it’s major and minor versions:

# uname -r
2.6.18-164.11.1.el5

To print the system architecture type i.e. whether the machine is 32 or 64 bit, use:

# uname -p
i686

The /proc/version file also contains the kernel information:

# cat /proc/version

Linux version 2.6.18-164.11.1.el5 (gcc version 4.1.2 20080704 

(Red Hat 4.1.2-46)) #1 SMP Wed Jan 20 07:39:04 EST 2010