Extending LVM By Adding New Disk To a Virtual Machine

In previous post, we have covered the way to make LVM and filesystem aware of the disk size increase that happen in the virtual machine layer. 

There is another way to increase LVM volume capacity, that is to add new disk into the system. 

1. First, shutdown the virtual machine

2. Add a new virtual disk size into the virtual machine manager

3. Start the virtual machine

4. Check the new disk availability for LVM

$ sudo lvmdiskscan

5. To be able to use the new disk, it needs to be converted into physical volume (PV)

$ sudo pvcreate <path to the new disk>

6. Check list of PVs. Memorize the PV name

$ sudo pvs

7. Extend the volume group using the new PV

$ sudo vgextend <VG name> <PV name>

We can get the name of the VG by using this command. This command also will show how much free space is now available in the VG.

$ sudo vgs

8. Increase the size of logical volume, to use 100% of the free space available inside VG, using this command

$ sudo lvextend -l +100%FREE <LV PATH>

We can get the full  path of LV using this command

$ sudo lvdisplay | grep Path

9. Now, make the filesystem aware that the partition size has been increased. The command to do this differ from filesystem to filesystem, but we include 2 of the most used (based on our experience) filesystem

For xfs:

$ sudo xfs_growfs <mountpoint>

For  ext4:

$ sudo resize2fs <mountpoint>

10. Verify that the mountpoint is now increase in size

$ df -Th

Extending Virtual Disk in a Linux Virtual Machine Using LVM

To increase a disk size in a virtual machine with Linux operating system configured with LVM, below are the steps (these steps were tested using virtualbox):

1. Power off the virtual machine

2. Increase the virtual disk size in the virtual machine using the virtual machine manager

3. Restart the virtual machine

4. Even though the virtual disk has been increased in size, but LVM is not aware of the change. To make LVM aware of the change, run pvresize command

$ sudo pvresize <pv name>

You can get the physical volume (PV) name by running "pvs" command

$ sudo pvs

5. Once the physical volume (PV) has been resized, run "vgs" to see the new volume group (VG) size

$ sudo vgs

6. Resize logical volume (LV) to make the new size available for us to use. Use below command to resize LV to use 100% of the free space available in VG

$ sudo lvextend -l +100%FREE <LV path>

You can get the LV path by running lvdisplay

$ sudo lvdisplay | grep Path

7. Now the partition is aware of the size change, but not the filesystem. Check the filesystem type and mountpoint using below command

$ df -Th

8. Depending on the filesystem type, extend your filesystem to suit the new partition size. 

For xfs:

$ sudo xfs_growfs <mountpoint>

and for ext4:

$ sudo resize2fs <mountpoint>

9. Verify that your filesystem is now using the new size

$ df -Th

Installing rancheros on virtualbox

Rancheros is a simple linux operating system, equipped with docker for easy deployment of docker in a virtual machine.

In this example, we will use virtualbox as our hypervisor.

First, download the rancheros iso from here

$ wget https://releases.rancher.com/os/v1.5.6/rancheros.iso

Then, fire up virtualbox and create a linux 64-bit virtual machine with 1GB memory, 8GB hard disk, and a bridged network.

Next mount the rancheros.iso file to the cdrom of the virtual machine we just created above, and boot the virtual machine.

Once booted, open the virtual machine console, change the password, and get the ip address of the virtual machine.

$ sudo passwd rancher

$ ip address

In this example, I will use 10.0.0.10 as the ip address of the virtual machine. Now, fire up your terminal, and ssh into the virtual machine.

$ ssh rancher@10.0.0.10

Once logged in, we will create a pair of ssh key for the user

$ ssh-keygen

We need to keep the private key in our host machine, so that we can use it to login to the virtual machine once we have installed rancheros to disk. So open another terminal, and download the private key we just generated above.

$ scp rancher@10.0.0.10:~/.ssh/id_rsa ~/rancher_id_rsa

Now we have to create a cloud-config.yml file, that is needed for rancheros installation to disk. We will have to include the ssh public key generated above, into the cloud-config.yml

$ echo -e "ssh_authorized_keys:\n  - $(cat ~/.ssh/id_rsa.pub)" > cloud-config.yml

Install rancheros to disk using ros command.

$ sudo ros install -c cloud-config.yml -d /dev/sda

Once finished, you can ssh into the rancheros on virtual machine's disk, by including the rancher_id_rsa file into your ssh command

$ ssh -i ~/rancher_id_rsa rancher@10.0.0.10

Once logged in, you can now start using docker.

$ docker version

Install and Use Vagrant on Linux Mint 19 with Virtualbox

Vagrant is a tool for building and managing virtual machine environments in a single workflow. With an easy-to-use workflow and focus on automation, Vagrant lowers development environment setup time, increases production parity, and makes the "works on my machine" excuse a relic of the past.

We can always install vagrant from the repository, but the one in the repository is quite an old version, which is 2.0.2. So we will download the latest version from https://www.vagrantup.com/downloads.html. Since they do not provide a package for ubuntu/mint, we will use debian package.

To download the installer

$ wget -c https://releases.hashicorp.com/vagrant/2.2.7/vagrant_2.2.7_x86_64.deb 

To install vagrant

$ sudo apt install ./vagrant_2.2.7_x86_64.deb -y

Download virtualbox, if you still have not install it

$ wget -c https://download.virtualbox.org/virtualbox/6.1.4/virtualbox-6.1_6.1.4-136177~Ubuntu~bionic_amd64.deb

Install  virtualbox

$ sudo apt install ./virtualbox-6.1_6.1.4-136177~Ubuntu~bionic_amd64.deb -y

Let's say we want to create an ubuntu bionic virtual machine (VM) using vagrant. First we have to run init

$ mkdir -p  vagrant/ubuntu-bionic

$ cd vagrant/ubuntu-bionic

$ vagrant init hashicorp/bionic64

$ vagrant up

The init command will create a standard Vagrantfile, which can be used to define the specs of virtual machine we want to make.

The up command will use the Vagrantfile, and create a VM out of it.

Once all the downloading is done, the VM will be created, and you can login into the box using ssh command

$ vagrant ssh

And within just a few commands, you already have a working virtual machine without having to do the standard operating system installation just like when you create a virtual machine using the traditional way.

Installing virtualbox 2.2.0 on ubuntu 8.10

To install virtualbox is fairly easy. Just follow the instructions below:

1. Open /etc/apt/sources.list and add this line deb http://download.virtualbox.org/virtualbox/debian intrepid non-free

2. Import sun public-key and register it using apt-key (wget is for downloading, apt-key is for registering the key to your machine)
$ wget -q http://download.virtualbox.org/virtualbox/debian/sun_vbox.asc -O - | sudo apt-key add -
OK

3. Update your system's package index file
$ sudo apt-get update

4. Install virtualbox 2.2
$ sudo apt-get install virtualbox-2.2

Done, that's all :)