VCHI initialization failed Raspberry Pi Fixed

vcgencmd get_mem arm VCHI initialization failed
Example showing VCHI initialization failed error

If when running vcgencmd on a raspberry pi you get VCHI initialization failed then you need to add the video group to your user. The vcgencmd tool requires you have this group role so without it, it will give VCHI initialization failed.

To add the user group to your user you can run:

sudo usermod -aG video <username>

Where <username> is the user you want to run the vcgencmd command with. This command adds the video group to the the user you specify.

Once you have ran the command any new logins will run the command successfully. Logging out and back into the pi will let you use the command.

Why this problem occurs

This issue happens when you try and use the vcgencmd command with a user that isn’t a member of the video group. This typically happens when you create a new user for the raspberry pi and don’t give it the same groups that the pi user has.

The solution above fixes this by adding the correct video group to the created user.

Mysql workbench working with key based exchange mechanisms

It appears newer linux sshd configs (fedora 22) by default include a smaller set of key exchange based mechanisms that they have turned on.

This means that it gives errors saying it is unable to connect to the server. To fix this you need to enable some of the older key exchange mechanisms,

Adding this line to /etc/ssh/sshd_config and restarting the sshd server will fix it

KexAlgorithms curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1

Credits to: http://serverfault.com/questions/692060/mysql-workbench-with-debian-jessie-tcp-ip-over-ssh-does-not-work

Install Virtualbox guest additions on Fedora 21 XFCE

Installing via the normal route didn’t work and meant I couldn’t easily resize the screen. Doing the below allowed me to use the resize easily.

  1. Install rpmfusion on fedora
  2. run `sudo yum install akmod-VirtualBox VirtualBox-guest`
  3. run `cd /usr/src/akmods`
  4. run `sudo rpm -ivh VirtualBox-*.rpm`

Once this was installed, rebooting will give you access to shared folders and fullscreen mode

Found the fix on the fedora forums for fedora 19

Selection/Click and drag doesnt work in Gmail – Opera

In opera normally click and drag or selection doesn’t work. This is because in opera Gmail serves up some CSS that breaks the display and stops you clicking and dragging text.

To fix this, you can enable opera’s list of JavaScript changes, to make popular sites work. This is done by visiting: http://www.opera.com/docs/browserjs/

Could not access network location \Hewlett-Packard\\

When trying to install MySQL Server it failed with the message “Could not access network location \Hewlett-Packard\\”

After some searching it turns out this is a common issue where HP have inserted a registry entry with the install path of “\Hewlett-Packard\\” which isnt a valid location. This can be resolved by removing this entry. This is safe to do so.

If you dont know what the registry is, you probably want to talk to someone who does or do some research, but using the search tool to find “\Hewlett-Packard\\” and delete the entry should fix the issue. It could be in a number of places but will likely be under an “uninstall” path.

As usual, when playing with the registry, use caution, ask others if unsure, and back it up.

Full error log mysql installer gave me:

1:
1: Action 11:31:29: INSTALL.
1: 1: MySQL Server 5.6 2: {0B9D4C33-AC1B-4973-B754-FE9EAB03D327}
1: Action 11:31:29: FindRelatedProducts. Searching for related applications
1: Action 11:31:29: AppSearch. Searching for installed applications
1: Action 11:31:29: LaunchConditions. Evaluating launch conditions
1: Action 11:31:29: ValidateProductID.
1: Action 11:31:29: CostInitialize. Computing space requirements
1: Action 11:31:29: FileCost. Computing space requirements
1: Action 11:31:29: CostFinalize. Computing space requirements
1: Could not access network location \Hewlett-Packard\\.
1: Could not access network location \Hewlett-Packard\\.
1: 1: MySQL Server 5.6 2: {0B9D4C33-AC1B-4973-B754-FE9EAB03D327} 3: 3
1:
1: Final actions.
1: Install error

Using Nvidia Optimus on Fedora

If your computer is recent and has an i3/i5/i7 intel core and a Nvidia graphics card it likely uses Optimus technology. This smart piece of software turns off the power-hungry Nvidia graphics card and runs most programs on the integrated intel graphics chip. In laptops this can save a lot of power. However this solution is only available in windows 7 upwards.

The problem occurs when you are using an operating system that doesn’t support this, as in most cases both cards will run all the time, causing major battery drain. On laptops this can severely shorten the battery life.

However there is a solution to this called bumblebee. This piece of software aims to offer similar technology in Linux-based machines. I found many tutorials on how to install it and work and ended up reinstalling fedora (17 at the time) several times.

However, I found a post from the NC State University Technical Staff Exchange on how to install bumblebee for Fedora and Redhat based distributions. I used this before to install on Fedora 17 and now just today on Fedora 18. Previously I was having a lot of issues getting it to work on Fedora 18 and according to them “nouveau drivers do not work on fedora 18 at this time” which after following their guide and installing the Nvidia ones it started to work.

If you are running a laptop with a new intel core and Nvidia graphics card and are getting poor battery life, I suggest you looking into seeing if you have Optimus technology in your laptop, and if so try this.

However, there is a warning, you will be messing around with your display drivers which could cause your system to not be able to display any GUI. Back up everything before trying this.

As usual, if you have any questions, it worked for you or you have something to add to my post, leave a comment!

Tile windows like Windows 7 on XFCE

Windows 7 has a really nice feature that lets you tile a window to the left or right of the screen, allowing easier placement. This is normally activated with the Windows-(left, right, up down) Arrow key combination.

I had searched how to do this with XFCE for a while and today after upgrading to Fedora 18, XFCE 4.2 i found it.

If you go to Settings -> Window Manager -> Keyboard

There is a list of keyboard shortcuts, there is 4 towards the bottom called “Tile window to the (left, right, top, bottom)”. This is exactly what i wanted and have now assigned Windows-Left Arrow key and the other combinations to use this.

It’s a small thing, but makes resizing and moving windows around a lot quicker than manually doing it.