How to Configure LVM (Logical Volume Management) in Oracle Enterprise Linux (OEL)
In previous blog we have seen How to Install OEL 7.7 Click here to read more. And then Upgraded OEL 7.7 to 7.9 Click here to read more. In this blog post we will add new storage hard-disk in Linux Server to store user data. And we will see How to configure LVM (Logical Volume Management) over physical hard disk.
Main benefit of LVM is you can extend or reduce the filesystem as per your requirement without loss of any data and without downtime. When normal Linux partition is full and you need more space in mount point, then normal partition cannot be extended. You have to take a backup of that partition, delete that partition and again create that partition with more disk space, format and mount the partition and then restore that mount point data from the backup. This process requires down time. So this problem can be overcome by LVM. Even you can take Snapshot of Logical Volume and can be Restored if needed.
I have added new 50Gb Hard-disk to my VM. We will use this hard disk to create LVM. Reboot your VM machine in order to detect new attached hard disk in VM.
Use command fdisk -l to list the attached hard disk, New Unpartitioned disk /dev/sdb is visible on VM.
[root@test-machine02 ~]# fdisk -l
Disk /dev/sdb: 53.7 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Follow below steps to create partition using LVM
- n : add a new partition
- t : change a partition’s system id
- 8e : Hex code for Linux LVM
[root@test-machine02 ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0x4522ec84.
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-104857599, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-104857599, default 104857599):
Using default value 104857599
Partition 1 of type Linux and of size 50 GiB is set
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@test-machine02 ~]# fdisk -l /dev/sdb
Disk /dev/sdb: 53.7 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x4522ec84
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104857599 52427776 8e Linux LVM
[root@test-machine02 ~]#
Use below command to create Physical Volumes for LVM. Please note /dev/sda2 Hard disk is already partition in LVM during Linux OS installation and used as root directory.
[root@test-machine02 ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
[root@test-machine02 ~]#
[root@test-machine02 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 ol lvm2 a-- <49.00g 4.00m
/dev/sdb1 lvm2 --- <50.00g <50.00g
Use below command to create vg1 Volume Group, Volume group is the next layer in LVM structure. Basically, volume group contains the physical volumes you created.
[root@test-machine02 ~]# vgcreate vg1 /dev/sdb1
Volume group "vg1" successfully created
[root@test-machine02 ~]#
[root@test-machine02 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
ol 1 2 0 wz--n- <49.00g 4.00m
vg1 1 0 0 wz--n- <50.00g <50.00g
Use below command to create lvu01_vg1 & lvu02_vg1 Logical Volume each of 15 GB size, Logical Volume is the layer next to volume group in LVM structure. Logical volumes are nothing but block devices created from the volume group. It is a virtual disk partition and can be easily managed using LVM commands.
[root@test-machine02 ~]# lvcreate -L 15g -n lvu01_vg1 vg1
Logical volume "lvu01_vg1" created.
[root@test-machine02 ~]#
[root@test-machine02 ~]# lvcreate -L 15g -n lvu02_vg1 vg1
Logical volume "lvu02_vg1" created.
[root@test-machine02 ~]#
[root@test-machine02 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root ol -wi-ao---- <45.12g
swap ol -wi-ao---- <3.88g
lvu01_vg1 vg1 -wi-a----- 15.00g
lvu02_vg1 vg1 -wi-a----- 15.00g
[root@test-machine02 ~]# lvscan
ACTIVE '/dev/ol/swap' [<3.88 GiB] inherit
ACTIVE '/dev/ol/root' [<45.12 GiB] inherit
ACTIVE '/dev/vg1/lvu01_vg1' [15.00 GiB] inherit
ACTIVE '/dev/vg1/lvu02_vg1' [15.00 GiB] inherit
Now we are ready to create filesystem. As we have created two Volume Group lvu01_vg1 & lvu02_vg1, We will create two different filesystem ext4 & xfs. Create u01 & u02 in root directory and mount the filesystem.
[root@test-machine02 ~]# mkfs.ext4 /dev/vg1/lvu01_vg1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
983040 inodes, 3932160 blocks
196608 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2151677952
120 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
[root@test-machine02 ~]#
[root@test-machine02 ~]# mkfs.xfs /dev/vg1/lvu02_vg1
meta-data=/dev/vg1/lvu02_vg1 isize=256 agcount=4, agsize=983040 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0, sparse=0, rmapbt=0, reflink=0
data = bsize=4096 blocks=3932160, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@test-machine02 ~]#
[root@test-machine02 ~]# cd /
[root@test-machine02 /]#
[root@test-machine02 /]# mkdir u01
[root@test-machine02 /]# mkdir u02
[root@test-machine02 /]#
[root@test-machine02 /]# mount /dev/vg1/lvu01_vg1 /u01
[root@test-machine02 /]#
[root@test-machine02 /]# mount /dev/vg1/lvu02_vg1 /u02
[root@test-machine02 /]#
[root@test-machine02 /]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs tmpfs 2.0G 0 2.0G 0% /dev/shm
tmpfs tmpfs 2.0G 9.1M 2.0G 1% /run
tmpfs tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup
/dev/mapper/ol-root xfs 46G 3.4G 42G 8% /
/dev/sda1 xfs 1014M 246M 769M 25% /boot
tmpfs tmpfs 392M 0 392M 0% /run/user/0
/dev/mapper/vg1-lvu01_vg1 ext4 15G 41M 14G 1% /u01
/dev/mapper/vg1-lvu02_vg1 xfs 15G 33M 15G 1% /u02
Click here for Step by Step Install Oracle Enterprise Linux (OEL) 7
Click here for How to Upgrade Oracle Enterprise Linux (OEL) 7.7 to 7.9
Click here for How to Extend and Reduce LVM (Logical Volume Management)
Click here for Step by Step manually creation of an Oracle 19c Database on Linux 7
This document is just for learning purpose and always validate in the LAB environment first before applying in the LIVE environment.
Hope so you like this article!
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