How to create and extend logical volumes by using LVM on Ubuntu 21.04

To Create and Extend logical volumes by using LVM on Ubuntu 21.04

Introduction:

In Linux, the Logical Volume Manager (LVM) is a tool for virtualizing disks. It can create "virtual" hard drive partitions, which can be expanded, shrunk, or moved. It also allows you to use multiple small disks to create larger partitions. Prerequisite: lvm2 package

Step 1: Check the installed OS version by using the following command

root@linuxhelp:~# lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 21.04
Release:	21.04
Codename:	hirsute

Step 2: List all physical disk available in system by using the following command

root@linuxhelp:~# fdisk -l | grep /dev/sd
Disk /dev/sdc: 15 GiB, 16106127360 bytes, 31457280 sectors
Disk /dev/sdd: 10 GiB, 10737418240 bytes, 20971520 sectors
Disk /dev/sdb: 10 GiB, 10737418240 bytes, 20971520 sectors
Disk /dev/sda: 40 GiB, 42949672960 bytes, 83886080 sectors
/dev/sda1   2048    4095    2048    1M BIOS boot
/dev/sda2   4096 1054719 1050624  513M EFI System

Step 3: Open fdisk to create partions on /dev/sdb disk

root@linuxhelp:~# fdisk /dev/sdb

Welcome to fdisk (util-linux 2.36.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Create New Partition
Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): 

Using default response p.

Using default partition number and using entire disk space partition by pressing enter for all
Partition number (1-4, default 1): 
First sector (2048-20971519, default 2048): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-20971519, default 20971519): 

Created a new partition 1 of type 'Linux' and of size 10 GiB.




Change the partition type to Linux LVM 
Command (m for help): t

Selected partition 1
Hex code or alias (type L to list all): 8E
Changed type of partition 'Linux' to 'Linux LVM'.

View the created partition
Command (m for help): p
Disk /dev/sdb: 10 GiB, 10737418240 bytes, 20971520 sectors
Disk model: VMware Virtual S
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5da27853

Device     Boot Start      End  Sectors Size Id Type
/dev/sdb1        2048 20971519 20969472  10G 8e Linux LVM


Save the all changes made to the disks
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

Step 4: Open fdisk to create partions on /dev/sdc disk

root@linuxhelp:~# fdisk /dev/sdc

Welcome to fdisk (util-linux 2.36.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Create New Partition
Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): 

Using default response p.


Using default partition number and using entire disk space partition by pressing enter for all
Partition number (1-4, default 1): 
First sector (2048-31457279, default 2048): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-31457279, default 31457279): 

Created a new partition 1 of type 'Linux' and of size 15 GiB.


Change the partition type to Linux LVM 
Command (m for help): t
Selected partition 1
Hex code or alias (type L to list all): 8E
Changed type of partition 'Linux' to 'Linux LVM'.


View the created partition
Command (m for help): p

Disk /dev/sdc: 15 GiB, 16106127360 bytes, 31457280 sectors
Disk model: VMware Virtual S
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xfe1d405a

Device     Boot Start      End  Sectors Size Id Type
/dev/sdc1        2048 31457279 31455232  15G 8e Linux LVM

Save  the all changes made to the disks
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

Step 5: Create physical volume in /dev/sdb1 drive

root@linuxhelp:~# pvcreate /dev/sdb1
  Physical volume "/dev/sdb1" successfully created.

Step 6: Create physical volume in /dev/sdc1 drive

root@linuxhelp:~# pvcreate /dev/sdc1
  Physical volume "/dev/sdc1" successfully created.

Step 7: List the physical volume by using the following command

root@linuxhelp:~# pvs
  PV         VG Fmt  Attr PSize   PFree  
  /dev/sdb1     lvm2 ---  <10.00g <10.00g
  /dev/sdc1     lvm2 ---  <15.00g <15.00g

Step 8: Create the volume group named “myvg” with PVs contained

root@linuxhelp:~# vgcreate myvg /dev/sdb1 /dev/sdc1
  Volume group "myvg" successfully created

Step 9: List the volume group by using the following command

root@linuxhelp:~# vgs
  VG   #PV #LV #SN Attr   VSize  VFree 
  myvg   2   0   0 wz--n- 24.99g 24.99g

Step 10: Create logical volume named “mylv” with 20GB size in volume group “myvg”

root@linuxhelp:~# lvcreate -L 20G -n mylv myvg
WARNING: ext4 signature detected on /dev/myvg/mylv at offset 1080. Wipe it? [y/n]: y
  Wiping ext4 signature on /dev/myvg/mylv.
  Logical volume "mylv" created.

Step 11: View the volume group with details

root@linuxhelp:~# lvdisplay myvg
  --- Logical volume ---
  LV Path                /dev/myvg/mylv
  LV Name                mylv
  VG Name                myvg
  LV UUID                3s0Afz-7d2Q-Yhcp-rcbO-KozC-2qo0-QadjMr
  LV Write Access        read/write
  LV Creation host, time linuxhelp, 2021-11-13 00:59:16 +0530
  LV Status              available
  open                 0
 LV Size                20.00 GiB
  Current LE             5120
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0

Step 12: Format the logical volume “mylv” to ext4 file system

root@linuxhelp:~# mkfs.ext4 /dev/myvg/mylv
mke2fs 1.45.7 (28-Jan-2021)
Creating filesystem with 5242880 4k blocks and 1310720 inodes
Filesystem UUID: f26aa915-2f06-44cf-92fd-8202b05d7408
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
	4096000

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done   

Step 13: Mount the logical volume “mylv” to the directory /mnt

root@linuxhelp:~# mount /dev/myvg/mylv /mnt

Step 14: Viewing the mounted status by using following command

root@linuxhelp:~# df -h
Filesystem             Size  Used Avail Use% Mounted on
tmpfs                  195M  1.6M  194M   1% /run
/dev/sda3               39G  9.7G   27G  27% /
tmpfs                  974M     0  974M   0% /dev/shm
tmpfs                  5.0M  4.0K  5.0M   1% /run/lock
tmpfs                  4.0M     0  4.0M   0% /sys/fs/cgroup
/dev/sda2              512M  5.3M  507M   2% /boot/efi
tmpfs                  195M  116K  195M   1% /run/user/1000
/dev/mapper/myvg-mylv   20G   45M   19G   1% /mnt

Step 15: Open the fdisk to create partions on /dev/sdc disk

root@linuxhelp:~# fdisk /dev/sdd

Welcome to fdisk (util-linux 2.36.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Create New Partition
Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): 

Using default response p.

Using default partition number and using entire disk space partition by pressing enter for all
Partition number (1-4, default 1): 
First sector (2048-20971519, default 2048): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-20971519, default 20971519): 

Created a new partition 1 of type 'Linux' and of size 10 GiB.


Change the partition type to Linux LVM 
Command (m for help): t

Selected partition 1
Hex code or alias (type L to list all): 8E
Changed type of partition 'Linux' to 'Linux LVM'.

Save all the  changes made to the disks
Command (m for help): w

The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

Step 16: Extend the volume group with “/dev/sdd1” drive

root@linuxhelp:~# vgextend myvg /dev/sdd1
  Physical volume "/dev/sdd1" successfully created.
  Volume group "myvg" successfully extended

Step 17: List the volume group reflected that the 10 GB increased

root@linuxhelp:~# vgs
  VG   #PV #LV #SN Attr   VSize   VFree  
  myvg   3   1   0 wz--n- <34.99g <14.99g

Step 18: Extend the “mylv” logical volume by 10GB

root@linuxhelp:~# lvextend -L +10G /dev/myvg/mylv
  Size of logical volume myvg/mylv changed from 20.00 GiB (5120 extents) to 30.00 GiB (7680 extents).
  Logical volume myvg/mylv successfully resized.

Step 19: Use resize2fs command to change effect on logical volume

root@linuxhelp:~# resize2fs /dev/myvg/mylv
resize2fs 1.45.7 (28-Jan-2021)
Filesystem at /dev/myvg/mylv is mounted on /mnt; on-line resizing required
old_desc_blocks = 3, new_desc_blocks = 4
The filesystem on /dev/myvg/mylv is now 7864320 (4k) blocks long.

Step 20: List the mounted drives to see the changes in memory

root@linuxhelp:~# df -h
Filesystem             Size  Used Avail Use% Mounted on
tmpfs                  195M  1.6M  194M   1% /run
/dev/sda3               39G  9.7G   27G  27% /
tmpfs                  974M     0  974M   0% /dev/shm
tmpfs                  5.0M  4.0K  5.0M   1% /run/lock
tmpfs                  4.0M     0  4.0M   0% /sys/fs/cgroup
/dev/sda2              512M  5.3M  507M   2% /boot/efi
tmpfs                  195M  116K  195M   1% /run/user/1000
/dev/mapper/myvg-mylv   30G   44M   28G   1% /mnt

with this creation of logical volumes by using LVM on Ubuntu 21.04 comes to an end