Create and Mount LVM Volume
In this article we will look into creating LVM volume on remaining not partitioned space and formatting logical volume with ext4 file system . We also will look into mounting it via fstab. In our LAB we will use CentOS7 vm to demonstrate our steps.
Creating LVM Volume
Lets start by determining free space with parted command.
[root@localhost ~]# parted /dev/sda unit MiB print free Model: ATA QEMU HARDDISK (scsi) Disk /dev/sda: 8192MiB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 0.03MiB 1.00MiB 0.97MiB Free Space 1 1.00MiB 201MiB 200MiB primary xfs boot 2 201MiB 1201MiB 1000MiB primary linux-swap(v1) 3 1201MiB 2201MiB 1000MiB primary xfs 2201MiB 8192MiB 5991MiB Free Space
from the output we can see that we already have 3 partitions / /boot and swap. We also have 6G of free space.
We will now created 4th partition with parted. The size will be 660G
parted /dev/sda mkpart primary 2308 3000
And now we can see that partition is created.
[root@localhost ~]# parted /dev/sda unit MiB print free Model: ATA QEMU HARDDISK (scsi) Disk /dev/sda: 8192MiB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 0.03MiB 1.00MiB 0.97MiB Free Space 1 1.00MiB 201MiB 200MiB primary xfs boot 2 201MiB 1201MiB 1000MiB primary linux-swap(v1) 3 1201MiB 2201MiB 1000MiB primary xfs 4 2201MiB 2861MiB 660MiB primary 2861MiB 8192MiB 5331MiB Free Space
Our next step would be to create physical volume on /dev/sda4 partition
[root@localhost ~]# pvcreate /dev/sda4 -v Set up physical volume for "/dev/sda4" with 1351680 available sectors Zeroing start of device /dev/sda4 Writing physical volume data to disk "/dev/sda4" Physical volume "/dev/sda4" successfully created
[root@localhost ~]# vgcreate -v VGdemo /dev/sda4 Adding physical volume '/dev/sda4' to volume group 'VGdemo' Archiving volume group "VGdemo" metadata (seqno 0). Creating volume group backup "/etc/lvm/backup/VGdemo" (seqno 1). Volume group "VGdemo" successfully created
We will now create logical volume demovol1 of size lets say 250M for now. We will go over on how to expand this volume at the later time.
[root@localhost ~]# lvcreate -L 250M -n demovol1 VGdemo -v Finding volume group "VGdemo" Rounding up size to full physical extent 252.00 MiB Archiving volume group "VGdemo" metadata (seqno 1). Creating logical volume demovol1 Creating volume group backup "/etc/lvm/backup/VGdemo" (seqno 2). Activating logical volume "demovol1". activation/volume_list configuration setting not defined: Checking only host tags for VGdemo/demovol1 Creating VGdemo-demovol1 Loading VGdemo-demovol1 table (253:0) Resuming VGdemo-demovol1 (253:0) Wiping known signatures on logical volume "VGdemo/demovol1" Initializing 4.00 KiB of logical volume "VGdemo/demovol1" with value 0. Logical volume "demovol1" created.
Next step is formatting our newly created LVM volume with ext4
[root@localhost ~]# mke2fs -t ext4 /dev/VGdemo/demovol1 mke2fs 1.42.9 (28-Dec-2013) Discarding device blocks: done Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=0 blocks, Stripe width=0 blocks 64512 inodes, 258048 blocks 12902 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=33816576 32 block groups 8192 blocks per group, 8192 fragments per group 2016 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729, 204801, 221185 Allocating group tables: done Writing inode tables: done Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done
Mount using fstab
First lets determine UUID using tune2fs command
[root@localhost ~]# tune2fs -l /dev/VGdemo/demovol1 | grep UUID Filesystem UUID: cac53166-6455-4e16-8b92-5d7c68fc1cf3
Create directory that we want to use for mounting our new share.
mkdir /mymntdir
Lets now edit fstab file and add entry for our new mount
vi /etc/fstab UUID=cac53166-6455-4e16-8b92-5d7c68fc1cf3 /mymntdir ext4 defaults 0 0
Now in order to mount our newly created share we run mount -a
[root@localhost ~]# mount -a [root@localhost ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 997M 846M 151M 85% / devtmpfs 489M 0 489M 0% /dev tmpfs 497M 0 497M 0% /dev/shm tmpfs 497M 6.5M 491M 2% /run tmpfs 497M 0 497M 0% /sys/fs/cgroup /dev/sda1 197M 99M 99M 50% /boot /dev/mapper/VGdemo-demovol1 241M 2.1M 222M 1% /mymntdir