How to Attach and Mount an EBS volume to EC2 Linux Instance

AWS allows you to create new EBS volumes and you can attach it to instances for extra storage. However, to make it usable as storage inside the instance, you need to mount it to a specific folder.

Mount an EBS volume to EC2 Linux

In this tutorial, we will teach you how to attach and mount an EBS volume to ec2 Linux instances.

Follow the steps given below carefully for the setup.

Step 1: Head over to EC2 –> Volumes and create a new volume of your preferred size and type.

Note: Make sure the EBS volume and the instance are in the same zone.

Step 2: Select the created volume, right-click and select the “attach volume” option.

Step 3: Select the instance from the instance text box as shown below.

Step 4: Now, login to your ec2 instance and list the available disks using the following command.

 lsblk

The above command will list the disk you attached to your instance.

Step 5: Check if the volume has any data using the following command.

sudo file -s /dev/xvdf

If the above command output shows “/dev/xvdf: data“, it means your volume is empty.

Step 6: Format the volume to the ext4 filesystem using the following command.

sudo mkfs -t ext4 /dev/xvdf

Step 7: Create a directory of your choice to mount our new ext4 volume. I am using the name “newvolume”

sudo mkdir /newvolume

Step 8: Mount the volume to “newvolume” directory using the following command.

sudo mount /dev/xvdf /newvolume/

Step 9: cd into newvolume directory and check the disk space for confirming the volume mount.

cd /newvolume
df -h .

The above command would show the free space in the newvolume directory.

To unmount the volume, you have to use the following command.

umount /dev/xvdf

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Automount EBS Volume on Reboot

By default on every reboot, the  EBS volumes other than root volume will get unmounted. To enable automount, you need to make an entry in the /etc/fstab file.

Step 1: Back up the /etc/fstab file.

sudo cp /etc/fstab /etc/fstab.bak

Step 2: Open /etc/fstab file and make an entry in the following format.

device_name mount_point file_system_type fs_mntops fs_freq fs_passno

For example,

/dev/xvdf       /newvolume   ext4    defaults,nofail        0       0

Step 3: Execute the following command to check id the fstab file has any error.

sudo mount -a

If the above command shows no error, it means your fstab entry is good.

Now, on every reboot, the extra EBS volumes will get mounted automatically.

Add Multiple EBS Volumes To EC2 Instance

You can add more than one EBS volumes to an ec2 instance as an additional disk. You can follow the same steps explained above and the only difference will be the disk name that you get from the lsblk command.

Here is an example output having two EBS volumes attached to an instance.

How Many EBS volumes can I attach to an Instance?

You can attach a maximum of 20 EBS volumes to the instance. However, limit the maximum volumes to have optimal performance. Also, plan your instance capacity based on the workload you are trying to run.

For example, databases require high IOPS for high read-write rates. IOPS depends on the disk size. Higher the size, the higher the IOPS.

Also, it is recommended to take snapshots of EBS volumes for high data high availability and restore option. Check out EBS snapshot automation article for strategies and restore options.

That’s how you mount and unmount EBS volumes in your ec2 instances. If you get any error during the setup, please feel free to contact us in the comment section.