How to find what dns server your using Ubuntu
If you need to know what dns servers you are using on Ubuntu then this command will help:
Ubuntu Server
How to rotate a PDF from the command line using Ubuntu / Linux
You might want rotate an image from the command line using the command line in Ubuntu. This is really usefull if you are stripting pdf manipulations. Then Happy rotating.
How to test if Bacula-fd is running
I just installed a new Bacula client but for some reason the server could not connect to it. I found this out by trying to get the status of the client on the server with the following command: Here is the things that I checked on the server. Step 1 – Check that the service … Read more
How to repair / restore Grub on Ubuntu using Live CD
I just upgraded Ubuntu and selected the wrong location to install Grub onto. Basically, I installed Grub on /dev/sda1 and not /dev/sda and so I need to repair and installing grub. I got out an Ubuntu installer cd which is essential a live cd and booted in it up. Then mounted the sda1 partition: Grub … Read more
Where you should install grub? sda or sda1
If you are install Grub – you will might be given the choice of: The answer is to install it on /dev/sda Note – If you install grub on a partition (such as sda1) it will only work if you are are chain-loading your bootloader.
How to generate a random mac address on Ubuntu command line
If you are creating a KVM host you can sometimes get the error such XML error: expected unicast mac address. Basically, you if you have manually entered a mac address which meets the Unicast standard then it will cause problems. Here is a quick way of generating a proper MAC Address:
How to remove exif metadata from jpegs using php or command line
There is a method of hacking php using a security flaw in php in how it handles exif meta data embedded in jpeg, png or gif images. You describe this as an EXIF injection attack. As a precaution it is a good idea to strip all EXIF information from any images that are uploaded to … Read more
a2ensite ERROR: Site www.example.com does not exist! Ubuntu 13.10
On our Ubuntu 13.10 server, I had created an apache configuration file for a virtual host however, I could not enable it using a2ensite. The file was here: I tried to enable it: However, the command complained that ERROR: Site www.example.com does not exist! The files clearly exists. It turns out the this command only … Read more
How to detect multiple dhcp servers on network using wireshark and Ubuntu
We just had a problem with our DHCP server and there seems to be another dhcp server on the network. To find this I used Wireshark on my Ubuntu machine to find the problem. 1 – Install wireshark 2 – Launch wireshark with permissions to read the network interfaces. You can either do this by … Read more
How to remove old kernels which are not used – Ubuntu
If you need to remove all the old kernels which were not currently being used to free up some space on the boot partition then this will do it for you.