Create LVM volume from multiple disks

Recently I had to crate an Amazon EC2 Instance with a storage capacity of 5Tb, unfortunately, Amazon only allows us to create 1Tb volumes so I had to create 5 volumes, attach them to the instance and create a 5Tb LVM device.

My instance was running Ubuntu and I hat to install the lvm2 package:

apt-get install lvm2 

The volumes attached to my instance where named from /dev/xvdg to /dev/xvdk

to find the names you can use the command:

fdisk -l

First we have to prepare our volumes for LVM with:

pvcreate /dev/xvdg /dev/xvdh /dev/xvdi /dev/xvdj /dev/xvdk

You can run the following command to check the result:

pvdisplay

The next step is to create a volume group, I used the command:

vgcreate storage /dev/xvdg /dev/xvdh /dev/xvdi /dev/xvdj /dev/xvdk 

And used the command:

vgdisplay

to check the result, you can also use:

vgscan 

Now we need to create the logical volume, in this case I wanted to use the entire available space so, I used the command:

lvcreate -n data -l 100%free storage

And

lvdisplay 

to check the new volume if every thing goes well it should be on /dev/storage/data 

you can also use the command 

lvscan

Now you just have to format the new device, you can use:

mkft -t ext4 /dev/storage/data

When ready you can mount it with:

mout /dev/storage/data /mnt

Increase LVM Volume

This is how I did it on a VMWare Machine but the procedure should be the same for a phisical machine:

First off, VMWare, like many other hypervisors, allows to create a second HDD on the fly while the vm is running.

Once that was done, login into the server and:

# echo “- – -” > /sys/class/scsi_host/host#/scan

partprobe should also do the trick

Just to see that the new disk is available use:

# fdisk -l

In this case it was /dev/sdb

create a new partition with

# fdisk /dev/sdb

press n and then w

Format the new partition:

# mkfs.ext3 /dev/sdb1

list the volume groups:

# vgs

add new physical volume

# pvcreate /dev/sdb1

extend the default volume group from the vgs command

# vgextend VolGroup /dev/sdb1

check to see pv and vg has another volume with:

# vgs

And list logical volumes

# lvdisplay

extend my / volume by the entire size of /dev/sdb1

# lvextend /dev/VolGroup/lv_root/dev/sdb1

resize filesystem to match vol size increase

# resize2fs /dev/VolGroup/lv_root

(requires a 2.6 kernel to resize while fs running)