Working with Logical Volume Management

Start an interactive root shell with sudo. Use fdisk to create a new default partition of type 8e on /dev/xvdb and /dev/xvdc. Create the first:

sudo -i
fdisk /dev/xvdb

Use the n command and choose all the defaults to create a new partition:

Command (m for help): n
Partition Type: p
Partition number (1-4, default 1): Press Enter to accept the default
First sector: Press Enter to accept the default
Last sector: Press Enter to accept the default

Use the t command to change to 8e (Linux LVM):

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'

Use the w command to write the changes to the partition table and exit:

Command (m for help): w

Now create the second:

fdisk /dev/xvdc

Use the n command and choose all the defaults to create a new partition:

Command (m for help): n
Partition Type: p
Partition number (1-4, default 1): Press Enter to accept the default
First sector: Press Enter to accept the default
Last sector: Press Enter to accept the default

Use the t command to change to 8e (Linux LVM):

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'

Use the w command to write the changes to the partition table and exit.

The result is that the /dev/xvdb1 and /dev/xvdc1 partitions of type 8e have been created.

Initialize the /dev/xvdb1 and /dev/xvdc1 LVM partitions as Physical Volumes with pvcreate. Inspect the Physical Volumes with pvs and pvdisplay:

pvcreate /dev/xvdb1 /dev/xvdc1
pvs
pvdisplay

Use vgcreate to create the volgroup Volume Group using the /dev/xvdb1 Physical Volume. Inspect volgroup with vgs and vgdisplay:

vgcreate volgroup /dev/xvdb1
vgs
vgdisplay

Use the lvcreate command to create two Logical Volumes, a 3 GB named datavol and a 1 GB named tempvol. Inspect them using lvs and lvdisplay commands:

lvcreate -n datavol -L3G volgroup
lvcreate -n tempvol -L1G volgroup
lvs
lvdisplay

Use lvremove to get rid of the tempvol, then run vgextend to expand the volume group. Create an ext4 filesystem on /dev/volgroup/datavol and mount it on /mnt/data. Use lvresize to extend the datavol Logical Volume and filesystem to the maximum size possible. Check everything afterward using the df and vgs commands:

lvremove /dev/volgroup/tempvol
Type 'y' and Enter to confirm 
vgs
vgextend volgroup /dev/xvdc1
vgs
vgdisplay
mkfs -t ext4 /dev/volgroup/datavol
mkdir /mnt/data
mount  /dev/volgroup/datavol /mnt/data
df -h /mnt/data
lvresize -r -L 9.99G /dev/volgroup/datavol
df -h

Unmount the /mnt/data directory with the umount command:

umount /mnt/data

Add the following line to /etc/fstab:

/dev/volgroup/datavol /mnt/data ext4 defaults 0 1

Use an editor like vim to add the line to the file:

vim /etc/fstab

Mount the device with the mount command. Use df to verify it mounted:

mount -a
df -h /mnt/data