Creating File System in Linux using LVM

File System using LVM in Linux

If you want to create a file system in linux using Logical volume manager.
Then this post will help you.

First of all, create a .vhd (virtual hard disk) using your storage system, size as you required like 5 GB.
Then follow below steps to create a file system :-


1.Then login your server and find newly created disk by using below command :-

[root@rhelnode1 /]# fdisk -l

If you can not find recently created 5GB disk. Then follow below easy steps to scan your storage path like HBA or SCSI :-

A. Find you scsi hosts

[root@rhelnode1 /]# ls /sys/class/scsi_host
host0  host1  host2

B.Scan each host ports :-

[root@rhelnode1 /]# echo "- - -"> /sys/class/scsi_host/host0/scan
[root@rhelnode1 /]# echo "- - -"> /sys/class/scsi_host/host1/scan
[root@rhelnode1 /]# echo "- - -"> /sys/class/scsi_host/host2/scan

C.now run you can run again fdisk command :-

[root@rhelnode1 /]# fdisk -l 2> /dev/null | egrep '^Disk'| grep -v mapper| grep -v identifier
Disk /dev/sda: 48.3 GB, 48318382080 bytes, 94371840 sectors
Disk label type: dos
Disk /dev/sdb: 5368 MB, 5368709120 bytes, 10485760 sectors
Disk /dev/sdc: 5368 MB, 5368709120 bytes, 10485760 sectors

D. To see block device mapping:-

[root@rhelnode1 /]# lsblk

NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT

fd0               2:0    1    4K  0 disk

sda               8:0    0  127G  0 disk

├─sda1            8:1    0  700M  0 part /boot

├─sda2            8:2    0  4.9G  0 part

│ └─vg01-swap   253:1    0  4.9G  0 lvm  [SWAP]

└─sda3            8:3    0 49.3G  0 part

  ├─rhel-root   253:0    0 13.7G  0 lvm  /

  ├─rhel-home   253:2    0 11.7G  0 lvm  /home

  ├─rhel-var    253:3    0   12G  0 lvm  /var

  └─rhel-backup 253:4    0 11.8G  0 lvm  /backup

sr0              11:0    1 1024M  0 rom

[root@amiteshjsk /]#

2.Now create a physical volume 

[root@rhelnode1 /]# pvcreate /dev/sdc
  Physical volume "/dev/sdc" successfully created.

3.Now create volume group and display you vg details

[root@rhelnode1 /]# vgcreate vg02 /dev/sdc
  Volume group "vg02" successfully created
[root@rhelnode1 /]# vgdisplay vg02
  --- Volume group ---
  VG Name               vg02
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               5.00 GiB
  PE Size               4.00 MiB
  Total PE              1279
  Alloc PE / Size       0 / 0   
  Free  PE / Size       1279 / 5.00 GiB
  VG UUID               vovDvR-WQUV-M0sE-OAZG-emAd-Vw77-Nzdkdv
   
[root@rhelnode1 /]# 

4. Now you can create desired size(Max 5GB) logical volumes.

So here I want create two logical volumes (2GB +2.5GB)

[root@rhelnode1 /]# lvcreate -L 2G -n sync vg02

  Logical volume "sync" created.

[root@rhelnode1 /]# lvcreate -L 2.5G -n backup vg02

  Logical volume "backup" created.

[root@rhelnode1 /]# 

5. Now format disk using xfs filesystem

[root@rhelnode1 /]# mkfs.xfs /dev/vg02/sync

meta-data=/dev/vg02/sync         isize=512    agcount=4, agsize=131072 blks

         =                       sectsz=512   attr=2, projid32bit=1

         =                       crc=1        finobt=0, sparse=0

data     =                       bsize=4096   blocks=524288, 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@rhelnode1 /]# mkfs.xfs /dev/vg02/backup

meta-data=/dev/vg02/backup       isize=512    agcount=4, agsize=163840 blks

         =                       sectsz=512   attr=2, projid32bit=1

         =                       crc=1        finobt=0, sparse=0

data     =                       bsize=4096   blocks=655360, 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@rhelnode1 /]# 

6. Now you can mount your logical volumes after creating directories 

[root@rhelnode1 /]# mkdir backup sync

[root@rhelnode1 /]# mount /dev/vg02/sync /sync

[root@rhelnode1 /]# mount /dev/vg02/backup /backup

[root@rhelnode1 /]# df -h

Filesystem               Size  Used Avail Use% Mounted on

/dev/sda2                 21G  3.2G   18G  16% /

devtmpfs                 1.2G     0  1.2G   0% /dev

tmpfs                    1.3G  144K  1.3G   1% /dev/shm

tmpfs                    1.3G  9.0M  1.2G   1% /run

tmpfs                    1.3G     0  1.3G   0% /sys/fs/cgroup

/dev/mapper/rhel-var     7.9G  1.3G  6.6G  16% /var

tmpfs                    247M  8.0K  247M   1% /run/user/0

/dev/mapper/vg01-data    2.0G   33M  2.0G   2% /data

/dev/mapper/vg02-sync    2.0G   33M  2.0G   2% /sync

/dev/mapper/vg02-backup  2.5G   33M  2.5G   2% /backup

[root@rhelnode1 /]# 

7. Now make entries in /etc/fstab file for auto mount after reboot-

[root@rhelnode1 /]# vi /etc/fstab

/dev/mapper/vg01-data     /data     xfs   defaults      0 2

/dev/mapper/vg02-sync     /sync     xfs   defaults      0 2

/dev/mapper/vg02-backup   /backup   xfs   defaults      0 2

Note:-

/etc/fstab contains 6 parameters per row. Each row represents one file system details. They are as below:

1.    Volume                 /dev/mapper/vg02-data

2.    Mount point          /data

3.    File system type   xfs

4.    Options                defaults

5.    Dump                  1,0 (for backup dump in failure) 

6.    Pass                     0,1,2 (for fsck sequence top or bottom)