EC2: EBS device id confusion (/dev/sdf vs. /dev/xvdf)

Question

I attached an EBS volume to my EC2 instance, turned it into a EXT3 file system, and successfully mounted it. However, I was thrown off a little bit initially mainly due to what

Answer 1

AWS provides the following message/warning when attaching a volume via the AWS Management Console:

Note: Newer linux kernels may rename your devices to /dev/xvdf through /dev/xvdp internally, even when the device name entered here (and shown in the details) is /dev/sdf through /dev/sdp.

I don't have any upstream source for this information handy, but Jay Rum's answer to the (not longer relevant) temporary problem EBS Disks starting as device /dev/xvde, but mapped as /dev/sda attributes this functionality to the xen-blkfront driver:

The "xen-blkfront" driver, which allows the virtual machines (i.e. the EC2 instances) to access the underlying block devices, traditionally mapped sda, sdb... to xvda, xvdb..., [...]

Finally, cyberx86' answer to How do I access the attached volume in Amazon EC2 provides a detailed and illustrated explanation of this device naming mismatch and how to deal with it, i.e. identify the currently available devices etc.

_{Note: This question had already been answered in Aug 24 '12, but that answer with 6 upvotes got deleted in May 01 '13 by the Community Moderator (i.e. a resp. automation process) for non transparent reasons (apparently because the User was removed) - anyway, I've added back a slight variation of the original content from my point of view.}