Linux Device Management

• Udev identifies new hardware and adds the entry of the hardware in the /dev folder

Linux File Soft and Hard Links

Exercise for Soft and Hard links

• Basic Setup

mkdir contents
cd contents
echo "hello world" >> text1.txt
echo "welcome to linux" >> text2.txt
ls -al .
cd ..
mkdir links
cd links
ln -s ../contents/text1.txt softtext1.txt
ln ../contents/text1.txt hardtext1.txt
ls -al .

• Delete the source and verify the links

cd contents/
rm text1.txt
cd ../links
cat softtext1.txt # This command will fail 
cat hardtext1.txt

• Create a softlink and a hardlink for text2.txt
  • Change the contents using the softlink and hardlink

inodes

• Number that represents the metadata
• Refer Here for more info on inodes

Linux Disk Mounting and Partition

• Disk
• FileSystem
• Mount

Exercise

• Find the disks connected to the linux

fdisk -l

• Attach 1GB disk to the existing ec2 instance and execute the following commands

fdisk -l 
ls -lart /dev

• Apply the filesystem to the disk (ext4/xfs)

mkfs -t ext4 /dev/xvdf

• Mounting the disk to some directory

df -h
mkdir /testdir
mount /dev/xvdf /testdir
df -h