Unable to find source of mounted volume on AWS EC2 instance

I have an Amazon EC2 instance running Ubuntu with a mount, /mnt/resources. When I run df -h, I can see the following:

/dev/sdb              414G  238G  155G  61% /mnt

I can't seem to figure out where this 400GB volume is coming from. I've looked in my ECS Volumes list, but there are only 8GB and 30GB instances.

Can someone please help me to figure out where the source of this mount is located?

EDIT

Running find /dev -lname \*/sdb reports the following:

/dev/disk/by-path/xen-vbd-2064
/dev/block/8:16
/dev/.udev/links/disk\x2fby-path\x2fxen-vbd-2064/b8:16
/dev/.udev/watch/29

josef.van.niekerk

Posted 2013-05-02T14:00:12.323

Reputation: 1 553

What size/type of instance is it? – Flup – 2013-05-02T14:00:47.317

I don't have much experience with EC2, but you can try with lsscsi to find out what /dev/sdb actually is. Another option to find out more is find /dev -lname \*/sdb. – Stefan Seidel – 2013-05-02T14:30:16.113

The EC2 instance is an m1.large instance. – josef.van.niekerk – 2013-05-02T15:15:37.417

Answers

I'm being a bit daft...after some reading up, I found that the Large instance has an additional physical volume mounted to the EC2 instance. Apparently AWS allows only 10GB root volumes, so the rest is on the /dev/sdb volume.

My misunderstanding was that this was going to be a Volume, listed in the EC2 console. Which is not the case.

josef.van.niekerk

Posted 2013-05-02T14:00:12.323

Reputation: 1 553

I had a similar problem, created a m2.medium instance with 400GB storage, but had only 8GB of space when I typed the 'df -h' command. Turns out that the command

sudo fdisk -l

...showed that the mounted root/boot device /dev/xvda1 actually was 400GB in size. It seems that when I created the instance, Amazon created a standard 8GB Linux image for it.

So I had to expand the partition to the size of the device. To do this I did the command

sudo resize2fs -f /dev/xvda1

Rebooting the instance and logging back into the shell, the 'df -h' command now shows nearly 400GB of available space. Problem solved.

Anachronist

Posted 2013-05-02T14:00:12.323

Reputation: 101