How to Change, Add, and Delete Users in Linux

Posted on March 25, 2014 by admin

Changing a users name:

sudo usermod -l new-username old-username

To change the users directory name do the following.

 sudo usermod -d /home/new-username

You might need to log in as root or another user to successfully execute the commands.

Adding a user:

sudo useradd -m newuser

The -m option create the new users home directory

Then to activate the user we need to setup a password.

sudo passwd newuser

Enter and reenter the password and your done.

If you need to add the user to a certain group(s) (sudo?) you can do that with usermod

sudo usermod -G sudo,othergroups newuser

Deleting a user:

sudo userdel -r username

The “-r” option deletes the users mail and home directory. If you wanted to keep them then just discard that option.

Installing Raspbian on Raspberry Pi from the Linux Command Line

Posted on March 25, 2014 by admin

First download the Rasbian zip from here.

Unzip the zipped file.

unzip 2014-01-07-wheezy-raspbian.img

You need to find your sdcard name. If you don’t now how to, take a look at this post.

Next format your card as Fat32.

Now write the image to the sdcard with the following command. Replace the mmcblk0 part of “of=/dev/mmcblk0” with your drive name.

sudo dd if=~/2014-01-07-wheezy-raspbian.img of=/dev/mmcblk0 bs=4M

It will not display any information until it is finished, so be patience.

Once it is complete, eject it and plug it into your Raspberry Pi and boot it up.

Finding a Drives Name in Linux From the Command Line

Posted on March 25, 2014 by admin

There are a few different ways to find out a drives(sdcard, usb drive, external hard drive) name.

dmesg command

One way to do it is to look at dmesg. Insert your drive and then run the command. It displays a lot of info, what we are interested in is the end which should say something about your drive.

dmesg

[ 4443.109976] mmc0: new high speed SDHC card at address aaaa
[ 4443.111857] mmcblk0: mmc0:aaaa SU04G 3.69 GiB 
[ 4443.120836]  mmcblk0: p1 p2
[ 4453.045338] EXT4-fs (mmcblk0p2): recovery complete
[ 4453.086165] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[ 4453.086184] SELinux: initialized (dev mmcblk0p2, type ext4), uses xattr

This tells us that the device is mmcblk0. The “p2” at the end is the partition number.

df Command

Another way to do it is to run the df command.
Run the below command without your drive plugged in.

df -h

it’ll return something like this

Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root   50G   12G   36G  24% /
devtmpfs                 1.9G     0  1.9G   0% /dev
tmpfs                    1.9G  600K  1.9G   1% /dev/shm
tmpfs                    1.9G  1.0M  1.9G   1% /run
tmpfs                    1.9G     0  1.9G   0% /sys/fs/cgroup
tmpfs                    1.9G   28K  1.9G   1% /tmp
/dev/sdb1                477M  115M  333M  26% /boot
/dev/mapper/fedora-home   76G   45G   23G  87% /home

The above command returns all the partitions that are mounted on your computer.
Now mount your drive and run the command again, it should show your drive at the bottom.

[me@fedora ~]$ df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root   50G   12G   36G  24% /
devtmpfs                 1.9G     0  1.9G   0% /dev
tmpfs                    1.9G  600K  1.9G   1% /dev/shm
tmpfs                    1.9G  1.1M  1.9G   1% /run
tmpfs                    1.9G     0  1.9G   0% /sys/fs/cgroup
tmpfs                    1.9G   28K  1.9G   1% /tmp
/dev/sdb1                477M  115M  333M  26% /boot
/dev/mapper/fedora-home   76G   45G   23G  87% /home
/dev/mmcblk0p2           3.6G  2.3G  1.1G  69% /run/media/me/fc522c75-9sws

You can see that the bottom one “/dev/mmcblk0p2 ” is the partition of the drive you just plugged in.

Using fdisk

You can also use fdisk.

sudo fdisk -l

It will return something similar to the following.

Disk /dev/mapper/fedora-home: 78.8 GiB, 191931351040 bytes, 374865920 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disk /dev/mmcblk0: 3.7 GiB, 3965190144 bytes, 7744512 sectors

The bottom section is the drive “mmcblk0”.

Using lsblk

lsblk is another cool tool to list drives and partions. When run with the -p option it shows the path to the drive and partition.

Example output of what you may get with “lsblk -p”

admin@localhost:~$ lsblk -p
NAME                              MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
/dev/nvme1n1                      259:0    0   450G  0 disk  
├─/dev/nvme1n1p1                  259:1    0   499M  0 part  
├─/dev/nvme1n1p2                  259:2    0   100M  0 part  
├─/dev/nvme1n1p3                  259:3    0    16M  0 part  
└─/dev/nvme1n1p4                  259:4    0 449.3G  0 part  
/dev/nvme0n1                      259:5    0   477G  0 disk  
 ├─/dev/nvme0n1p1                  259:6    0   512M  0 part  /boot/efi
 ├─/dev/nvme0n1p2                  259:7    0   732M  0 part  /boot
 └─/dev/nvme0n1p3                  259:8    0   400G  0 part  
   └─/dev/mapper/vg-root           253:1    0   391G  0 lvm   /
   └─/dev/mapper/vg-swap_1         253:2    0   7.9G  0 lvm   [SWAP]
admin@localhost:~$

How To Make a Live Bootable Fedora Thumb Drive in Linux

Posted on March 10, 2014 by admin

Insert your thumb drive into the computer.

We need to find out where the thumb drive is mounted. We can do this with the “df” command as shown below or you can find it in dmesg.

So if we run the df command

df -h

It returns something like this

[me@fedora ~]$ df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root   50G   11G   37G  23% /
devtmpfs                 1.9G     0  1.9G   0% /dev
tmpfs                    1.9G  1.2M  1.9G   1% /dev/shm
tmpfs                    1.9G  1.1M  1.9G   1% /run
tmpfs                    1.9G     0  1.9G   0% /sys/fs/cgroup
tmpfs                    1.9G   52K  1.9G   1% /tmp
/dev/sdb1                477M  115M  333M  26% /boot
/dev/mapper/fedora-home  176G  125G   42G  75% /home
/dev/sdc1                3.8G  3.2G  592M  85% /run/media/me/136A-7360
[me@fedora ~]$

Note that the bottom one is the thumb drive /dev/sdc1 yours may differ.

Now that we know where the drive is mounted we can write the image to the thumb drive.

Change the path in “if=/” to the path to your Fedora iso and change “of=/” to you thumb drive path

su -c "dd if=/home/me/Downloads/Fedora-Live-x86_64-20-1.iso of=/dev/sdc bs=8M"

It will take a couple of minutes to complete and it will not give you any information until it is finished.

Congratulations, you now have a live working Fedora thumb drive.

Create a Bootable OS X Thumb Drive on Linux

Posted on July 11, 2013 by admin

NOTE: This is a post has not been completely tested. So use at your own risk. This text will be removed once the post is completely tested.

What you need

InstallESD.dmg
7zip installed on your computer
Thumb Drive with 8gb of space on it
A few other things installed

Getting Ready

So first we need to make sure we have a few things installed.

yum install hfsplusutils gparted p7zip dmg2img

on Debian based systems use

sudo apt-get install hfsplus hfsprogs hfsutils gparted p7zip-full

Now that we have all the tools we need we can move on.

Navigate to were your InstallESD.dmg file is. Then run the following command.

7z x InstallESD.dmg

After it is finished cd into the InstallMacOSX.pkg

cd InstallMacOSX

now run

dmg2img InstallESD.dmg

Now you have a new file called InstallESD.img.

Open up Gparted (or your favorite disk tool) and find your thumb drive. Format the drive with a GUID Partition Table and make sure it is HFS+. When it is finished formating, Find the thumb drive and unmount it, and then click restore. It is under the “More actions” button on the top right. Find your InstallESD.img file and click Restore.
You are now finished. Have Fun!

How to Install VirtualBox on Fedora in 10 Steps

Posted on April 26, 2013 by admin

1. Open a terminal and change to the root user

su -

2. Then cd into the following directory

cd /etc/yum.repos.d/

3. Install wget.

yum install wget

4. Download the repo files with wget.

wget http://download.virtualbox.org/virtualbox/rpm/fedora/virtualbox.repo

5. Install the dependencies.

yum install binutils gcc make patch libgomp glibc-headers glibc-devel kernel-headers kernel-devel dkms

6. Update your computer.

yum update

7. Install VirtualBox.

yum install VirtualBox-4.2

8. Add the VirtualBox user to the vboxusers group

usermod -a -G vboxusers user_name

9. Reboot your computer.

reboot

10. Enjoy. If you run into problems try the following.

/etc/init.d/vboxdrv setup

Note:
I have created a script that will do all this for you, download here. All you need to do is the following 3 commands.

cd /pathto/fedora-vb-installer.sh
chmod +x fedora-vb-installer.sh
sudo ./fedora-vb-installer.sh

How to Setup a Cron Job

Posted on February 12, 2013 by admin

There are a couple ways to set up a cron job. If you have a script that you want to run ever so often, you could drop it in one of the cron directories, like cron.daily, or cron.weekly. These are located in /etc. Another way to do it is to use crontab.

To setup a cron job in crontab type

crontab -e

and then,

*/30 * * * * /path/to/yourscript.sh

The “*/30” makes the script run every 30 minutes. Below gives you a better idea of how the line works. The asterisk (*) specifies all possible values for a field, but can/should be replaced with the time you want the script to execute.

* * * * * command to be executed

*(min) *(hr) *(DoM) *(month) *(week) /path/to/command_or_script.sh

min= Minute 0 – 50
hr = Hour 0-59
DoM = Day of month 0-31
month = Month 1-12
week = Day of Week 0-7, Sunday is 0 or 7

Below are a couple of examples of how to run a script or command.
Every minute.

* * * * * /path/to/script.sh

Every day 10 minutes after 1 in the morning,

10 1 * * * /path/to/command

Also, if you don’t want to be emailed the output of the command, you can simple append “>/dev/null 2>&1” to the end of the crontab line.
Example

0 * 1 * * /path/to/command/ >/dev/null 2>&1

How to Install XenServer Tools on Linux

Posted on January 29, 2013 by admin

This assumes you are connected to your XenServer with XenCenter. First you need to mount the xs-tools.iso on the system. To do this right click on the VM you want to install XenServer Tools on and click “Install XenServer Tools”

Then from the console tab do the following as the root user, or just type sudo before each command

mkdir /mnt/xs-tools

mount /dev/cdrom /mnt/xs-tools

cd /mnt/xs-tools/Linux/

bash install.sh

After it finishes, you need to reboot.

How to set a Static IP Address in Ubuntu and Debian

Posted on January 23, 2013 by admin

The first thing we need to do, is open our interfaces file. Execute the following from a terminal.

sudo vi /etc/network/interfaces

sudo nano /etc/network/interfaces

Then add or copy and paste the following.

auto eth0
iface eth0 inet static
        address 192.168.1.100
        netmask 255.255.255.0
        network 192.168.1.0
        broadcast 192.168.1.255
        gateway 192.168.1.1

Close the file. Now we need to change the DNS settings

sudo vi /etc/resolv.conf

sudo nano /etc/resolv.conf

Edit the nameserver line to something like the following.

nameserver 8.8.8.8

Close the file and then restart the networking stuff.

sudo /etc/init.d/networking restart

Incredigeek

Tag Archives: linux

How to Change, Add, and Delete Users in Linux

Changing a users name:

Adding a user:

Deleting a user:

Installing Raspbian on Raspberry Pi from the Linux Command Line

Finding a Drives Name in Linux From the Command Line

df Command

Using fdisk

Using lsblk

How To Make a Live Bootable Fedora Thumb Drive in Linux

Create a Bootable OS X Thumb Drive on Linux

How to Install VirtualBox on Fedora in 10 Steps

How to Setup a Cron Job

How to Install XenServer Tools on Linux

How to set a Static IP Address in Ubuntu and Debian