hammadattari/linux

It will cover the basics of Linux which is a must for every Computer student

Linux

It will cover the basics of Linux which is a must for every Computer student. For example, Becoming an administrator of IT infrastructure and also important for developers of any language.

Step-by-step Guide to Create New Partition when we Add new hard disk within Linux

1. Start fdisk:

   • sudo fdisk /dev/sdb (replace /dev/sdb with your disk device)

2. To create a new partition, use the following parameters:

• n (create a new partition)
• p (make it a primary partition)
• 1 (assign it as partition number 1)
• 2048 (set the first sector)
• +100G (specify the partition size)

3. Set the partition type to LVM:

• t (change partition type)
• 8e (LVM partition type)

4. Write changes:

• w (make revisions)

When adding a new hard drive to an Ubuntu server and creating LVM (Logical Volume Manager) on it, follow these steps:

1. Install LVM:

   • sudo apt-get install lvm2 (if not already installed)

2. Create a physical volume (PV):

   • sudo pvcreate /dev/sdb (replace /dev/sdb with your new disk device)

3. Create a volume group (VG):

   • sudo vgcreate myvg /dev/sdb (replace myvg with your desired VG name)

4. Create logical volumes (LVs):

   • sudo lvcreate -n mylv -l +100%FREE myvg
   • sudo lvcreate -n mylv -L 100G myvg (replace mylv with your desired LV name and 100G with your desired size)

5. Format and mount the LV:

   • sudo mkfs.ext4 /dev/myvg/mylv
   • sudo mount /dev/myvg/mylv /mnt

6. Add the LV to the /etc/fstab for persistent mount:

   • sudo lsblk -o +UUID (get the UUID of the LV)
   • sudo UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx\t/mnt/data\text4\tdefaults\t0\t0 (\t means press a tab)
   • e.g. UUID=30dbec69-b3d0-4ac3-9619-cf4a534bca09 /mnt ext4 defaults 0 0

7. Verify the deletion or mounted on /mnt

   • df -h
   • ls -al /mnt (files are shown)

Extending Root Partition with LVM

Table of Contents

1. Verify Partition on New Disk (/dev/sdd): This step checks for the newly created partition.
2. Create Physical Volume (PV): This command creates a PV using the partition.
3. Extend Volume Group (VG): This step expands the VG to include the new PV.
4. Identify Root Logical Volume (LV): Locate your root LV for resizing.
5. Resize the Logical Volume (LV): This command extends the LV using available free space.
6. Verify Available Space (Optional): (Optional step) Check if unallocated space is visible within the partition.
7. Identify Filesystem Type: Determine the filesystem type of your root partition (e.g., ext4, xfs).
8. Resize the Filesystem: Use the appropriate command (ext4: resize2fs, xfs: xfs_growfs) to resize the filesystem and utilize the extended space.
9. Verify Resize (Optional): (Optional step) Confirm that the size of your root partition has increased.

Verify Partition on New Disk

fdisk -l /dev/sdd

# Note the whole disk 5GB partitioned with name: /dev/sdd1

Create Physical Volume (PV)

pvcreate /dev/sdd1

Extend Volume Group (VG)

Add the new physical volume to the existing volume group :

vgextend <your_vg_name> /dev/sdd1

# Example: ubuntu-vg is root volum group
vgextend ubuntu-vg /dev/sdd1

Identify Logical Volume (LV)

List all logical volumes and locate the root LV:

lvdisplay

Resize Logical Volume (LV)

• Copy the path to the LV you want to extend (e.g., /dev/ubuntu-vg/ubuntu-lv)
• Extend the logical volume:

lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv or
lvextend -L +5G /dev/mapper/ubuntu--vg-ubuntu--lv

Resize Filesystem

1. Check the disk usage:

lsblk
df -h

2. Resize the Filesystem:

resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

3. Verify the updated disk usage:

df -h

# Example output:

# Note: The available space has increased from 24GB to 29GB.

Only 9 commands to LVM Remove form Physical Partition

Only Remove LVM but /dev/sdb1 is remains available for you. This is The Step by Step Style guide for Ubuntu Server.

Step 1: Backup your data

Before deleting any partitions, make sure to backup your important data to an external drive or cloud storage.

Step 2: List the LVM partitions and unmount partition

Open a terminal and run the command:

sudo lvdisplay


Sudo umount /mnt

This will list all the LVM partitions on your system.

Step 3: Identify the partition to delete

Note the name of the partition you want to delete (e.g., "my_partition").

Step 4: Deactivate the partition

Run the command:

sudo lvchange -an /dev/my_partition
e.g. lvchange -an /dev/mapper/myvg-mylv

Replace "my_partition" with the actual name of the partition.

Step 5: Remove the partition

Run the command:

sudo lvremove /dev/my_partition
e.g. lvremove  /dev/mapper/myvg-mylv

Replace "my_partition" with the actual name of the partition.

Step 6: Remove the volume group (VG)

If the partition was part of a VG, you need to remove the VG as well. Run the command:

sudo vgremove my_vg
e.g. vgremove myvg

Replace "my_vg" with the actual name of the VG.

Step 7: Remove the physical volume (PV)

If the partition was on a PV, you need to remove the PV as well. Run the command:

sudo pvremove /dev/sda1

Replace "/dev/sda1" with the actual device path of the PV.

Step 8: Update the LVM configuration

Run the command:

sudo vgscan --mknodes

This will update the LVM configuration and remove any remaining references to the deleted partition.

Step 9: Verify the deletion

Run the command:

sudo lvdisplay
lsblk