Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
Create a new ext3 file system using LVM
Answer:
To create a new ext3 partition using the Logical Volume Manager (LVM) is just easy with a few commands:
# lvcreate -L 100G -n /dev/vg0/vp0 (Assume volume group is vg0)
# mkfs -t ext3 -m 1 -v /dev/vg0/vp0Then you can mount the /dev/vg0/vp0 as usual.
Add Personal Package Archives (PPA) to the current repository in Ubuntu
Answer:
add-apt-repository is a helper script which adds an external APT repository to either /etc/apt/sources.list or a file in /etc/apt/sources.list.d/. It can also import the keys needed.
To get this tool, just a single command:
# sudo apt-get install python-software-properties
That is it.
How to format a JSON file using command line
Answer:
JSON (JavaScript Object Notation) is a very popular data exchange format nowadays and to pretty format (i.e. easy to read) a JSON file, you can use the following method:
# cat my.json | python -mjson.tool
That's all.
Disable a service in Ubuntu using upstart
Answer:
In newer version of Ubuntu such as 10.04, some services are managed by upstart and you cannot disable them by using the old method.
For example, to disable the OpenSSH server, you need to edit the file /etc/init/ssh.conf, comment out the following lines:
# start on filesystem
# stop on runlevel [!2345]
Then this service will not start when you reboot your machine next time. All the upstart configurations files are under this folder and feel free to try it out.
Show ignored files in Mercurial
Answer:
To show list of files are currently ignored by Mercurial, e.g. to check if your .hgignore is working.
You can use the following command in your working repository:
# hg st -i
