[sf-lug] Trying to determine the actual size of a USB drive

Rick Moen rick at linuxmafia.com
Tue Aug 30 15:06:36 PDT 2011

Quoting Mike Higashi (mhigashi at gmail.com):

> I'm wondering if you could use dd to copy the raw device to a image file
> on another disk, and see what the resulting file size is. This is a read
> operation for the flash chip, so you're not shortening the life cycle.

Make sure you remount with the 'ro' option before doing that.
Otherwise, the problem is that any read operation of a FAT-formatted
filesystem is _also_ a write operation.  Because atime gets updated.
(See:  http://www.linuxjournal.com/article/6867?page=0,2 )

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