ServerBuddies Support Blog

Using SED command line to delete line from a file.

d Delete pattern space. Start next cycle.

You can use the following one liner to remove one line (line 3) from a file.

This will remove line 3 form the file ~/.ssh/known_hosts

How to Disable IPv6 in Apache Server

If there is no reason to run Apache with IPv6 then disabling it is wasy. We need to make quick changes to the Listen directive.

By default, Apache will listen on all IPs, both IPv6 and IPv4. (Assuming your system has IPv6 support). This is controlled by the Listen directive:

Turn off IPv6 in Apache

To turn off IPv6 in Apache, just change the Listen directive to:

This will limit Apache to listening only to IPv4 connections. We can repeat this for port 443 if you want to stop Apache from listening for HTTPS on IPv6.

Finding help content for MySQL databases administration.

Run ‘help contents’ for a list of all accessible topics

To go to the individual catefories run the following example command.

Creating and editing users in MySQL from shell prompt.

First we need to login into MySQL server as root.

Will be prompted for your MySQL root password (note this is not the same as the server root password).

Next we need to flush the privileges which reloads the ‘user’ table in MySQL - do this each time you add or edit users.

To give the user buddy select permission on all the databases, this allows the user to read, but not edit and delete.

The GRANT statement enables system administrators to create MySQL user accounts and to grant rights to accounts. To use GRANT, you must have the GRANT OPTION privilege, and you must have the privileges that you are granting. The REVOKE statement is related and enables administrators to remove account privileges.

Backup using the dd command

`dd’: Convert and copy a file

`dd’ copies a file (from standard input to standard output, by default)with a changeable I/O block size, while optionally performing conversions on it. Synopses:

For instance, to make an exact clone of the /boot partition to a backup file, you could use:

We can also use bzip2 to compresses files and then bunzip2 (or bzip2 -d) decompresses all specified files.

To clone one hard disk to another first use fdisk to recreate the appropriately-sized partitions, on the new disk and then use dd to do the actual cloning.