Is the EBS volume mounted ? and where?

Question

In my EC2 instance, that is attached to a volume EBS of 100GB, I run this command:

[ec2-user ~]$ lsblk

NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
xvda    202:0    0  100G  0 disk
└─xvda1 202:1    0    8G  0 part /

Here is the file /etc/fstab:

UUID=ue9a1ccd-a7dd-77f8-8be8-08573456abctkv       /   ext4    defaults       1       1

I want to understand: why only the volume of 8GB has a mount point ? Also, is the fact of mounting a volume on root '/', means that all the content of root is being stored on EBS volume?

Answer 1

I want to understand: why only the volume of 8GB has a mount point ?

Because additional volumes are not formatted/mounted by default. AWS does not know whether you'd like to have ext4 or NTFS or something else as well as which mount point you'd like to have.

Also, is the fact of mounting a volume on root '/', means that all the content of root is being stored on EBS volume?

Yes if you have EBS-backed instance (unlike so-called instance-backed instances) and if you do not have other volumes mounted (not to be confused with 'attached')

p.s. as far as I see, you initially had created 8GB volume then resized it via AWS console to 100GB. Pls note you resized the EBS volume (xvda) but did not resize the partition (xvda1). AWS will not resize it automatically by the same reason: it doesn't know how you're going to use the extra space.