Did you mess with your fstab at all? What were you doing last time before shutdown?
I highly doubt glibc would just 'vanish'
Unless there is a possibility of the drive going 'bad'? You might wanna boot into rescue mode and run fsck on your / partition to see if something is terribly wrong. Also, if possible, boot up into rescue mode and grab a copy of your fstab for us, post it up. Last thing, see if that file actually exists at that point, if not, maybe look into symlinking it to that point.