Archive for category Tutorials

How to disable sleep or screen blank when closing laptop lids

Posted by on Saturday, 18 September, 2010

I have an awesome HDMI out on my laptop – works flawlessly on the TV. This is handy for watching movies and plugging into the big screen. problem is that I want to close the laptop lid, and that puts the laptop to sleep!
I’m using Gnome, so this tutorial is specific for that.

First of all, i went into System -> Preferences -> Power Management

This gives me the options of ‘sleep’, ‘shutdown’, or ‘blank’. This is great for the most part, but did not work when playing movies on an external screen with laptop lid. Also if i happened to just want to use an external screen plugged into the laptop for work things it wasnt going to work.
To fix this, i opened up console and typed in

gconf-editor

This brings up the power editor of gnome, sort of like windows registry edit.
I clicked on apps -> gnome-power-manager -> buttons
In here i found the one which was lid_ac – this means its the lid when the laptop is plugged into the AC. I right clicked on that, then clicked “Edit Key”. Changed the Value to be ‘nothing’ (the actual word nothing).
Bingo, this is now done. You can tweak other settings in here, when you click on them normally it has a description of what they do and what options work.
I would advise against deleting anything!


How to enable multi user in wordpress 3

Posted by on Wednesday, 23 June, 2010

Do your usual install on wordpress, and get it up and running. If you are not sure what that is, download the zip, upload the contents to your website, then point your browser at it to finish the configuration.
Once you have filled out your database information, and sorted themes etc you can then move onto the next step. Do not enable any plugins at this stage, some may be incompatible with multiuser!

Look for the file wp-config.php on your server, you need to edit it and add in one line to it.

define('WP_ALLOW_MULTISITE', true);

Once you have added it, refresh your dashboard and go to Network settings under Tools section. This will give you two Options
* Subdirectories as in http://yourdomain.com/someuser/
* Subdomains as in http://user.yourdomain.com

Most people will want to use subdomains, This will require a wildcard DNS entry however. That means just add an A record of * pointing to the IP of your server, then add in the apache config below before restarting.

ServerAlias *.yourdomain.com

Once you have done this you can go under the SuperUser menu and add a site in.

Some extra wordpress notes:
* make the plugins/themes folder writable by the web server. It needs to be owned by the same user not just chmod 777/666 for some reason on a lot/most systems. This is so it can read/write plugins etc without the FTP details. Using the FTP is a more secure option, however it can be painful and annoying to do.
* Not all plugins are compatible with multiuser
* Security can be a problem, one site gets compromised, all sites may be.


Keeping your SSH session alive

Posted by on Wednesday, 23 June, 2010

I’m working on servers all day everyday, mostly by SSH. This can be annoying when you switch tabs and then want to go back to another and its timed you out and dead.
A nice quick shortcut to kill that session is to type in ‘~.’ This needs to be on a new line so it wont hurt to press enter beforehand. You will not see it echo on screen, but it will kill the inactive/dead ssh session nicely.

Before you login again, if you are running Linux on your local machine, you can add the following into /etc/ssh/ssh_config

    ServerAliveInterval 5

This will send a packet every 5 seconds to keep the connection alive. Very handy. You can make that longer if you want to use less bandwidth and your servers are setup ok with a longer keep alive.

Once you have logged into your server you can edit the /etc/sshd_config and add in the following

TCPKeepAlive yes
ClientAliveInterval 60

This will keep things ticking over from the server point of view. Once you have added that in , restart the SSHD daemon with /etc/init.d/ssh restart . This will not kill your current SSH session, though it pays to logout and log back in again for it to take effect.

Do remember security, you do not want to leave your local machine alone, unlocked, with a live SSH session running logged in as root on a production server!