About formatting new EBS volume on Amazon AWS

Question

I don't have much experience with Linux and mounting/unmounting things. I'm using Amazon AWS, have booting up EC2 with Ubuntu image, and have attached a new EBS volume to the EC2. From the dashboard, I can see that the volume is attached to :/dev/sda1.

Now, I see from this guide from Amazon that the path will likely be changed by the kernel. So it's most likely that my /dev/sda1 device will be mounted on, maybe, /dev/xvda1.

So I logged in using terminal. I do ls /dev/ and I indeed see xvda1 on there. But I also see xvda. Now I want to format the device. But I don't know if the unformatted device is attached to xvda1 or xvda. I cannot list the content of /dev/xvda1 and /dev/xvda (it says ls: cannot access /dev/xvda1/: Not a directory). I guess I have to format it first.

I tried to format using sudo mkfs.ext4 /dev/xvda1. It says: /dev/xvda1 is mounted; will not make a filesystem here!.

I tried to format using sudo mkfs.ext4 /dev/xvda. It says: /dev/xvda is apparently in use by the system; will not make a filesystem here!

How can I format the volume?

EDIT:

The result of lsblk command:

NAME    MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda    202:0    0   8G  0 disk 
`-xvda1 202:1    0   8G  0 part /

I then tried to use the command sudo mkfs -t ext4 /dev/xvda, but the same error message appears: /dev/xvda is apparently in use by the system; will not make a filesystem here!

When I tried to use the command mount /dev/xvda /webserver, error message appears: mount: /dev/xvda already mounted or /webserver busy. Some website indicate that this also probably because a corrupted or unformatted file system. So I guess I have to be able to format it first before able to mount it.

Answer 1

First of all you are trying to format /dev/xvda1, which is root device. Why ??

Second if you have added a new EBS, then follow below steps.

List Block Device's

This will give you list of block device attached to your EC2 which will look like

[ec2-user ~]$ lsblk
NAME  MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
xvdf  202:80   0  100G  0 disk
xvda1 202:1    0    8G  0 disk /

Out of this xvda1 is the / (root) and xvdf is the one that you need to format and mount ( for the new EBS)

Format Device

 sudo mkfs -t ext4 device_name   # device_name is xvdf here

Create a Mount Point

 sudo mkdir /mount_point

Mount the Volume

 sudo mount device_name mount_point  # here device_name is /dev/xvdf 

Make an entry in /etc/fstab

 device_name  mount_point  file_system_type  fs_mntops  fs_freq  fs_passno  

Execute

 sudo mount -a

This will read your /etc/fstab file and if it's OK. it will mount the EBS to mount_point