EC2 Volume Attachment Error (Unix)

I am trying to follow the 10gen documentation for standing up MongoDB on an EC2 instance. I am encountering an error when trying to attach the newly created volumes to my instance.

I am trying to run the command

$ ec2-attach-volume vol-dac9c92f  -i i-19f359db -d /dev/sdh2

The error that I receive is the following

Client.InvalidParameterValue: Value (/dev/sdh2) for parameter device is invalid. /dev/sdh2 is not a valid EBS device name.

And the relevant part of the documentation is this

$ (i=0; \
> for vol in $(awk '{print $2}' vols.txt); do \
>   i=$((i+1)); \
>   ec2-attach-volume $vol -i i-11eee072 -d /dev/sdh${i}; \
> done)

This command executes successfully (notice the absence of the id number)

$ ec2-attach-volume vol-dac9c92f  -i i-19f359db -d /dev/sdh

If anyone could point out what I may be doing wrong I would be greatly appreciative.

-James