Richard Owlett <rowl...@cloud85.net> writes: > Roger Leigh wrote: >> On Fri, Apr 05, 2013 at 05:42:32AM -0700, sting wing wrote: >>> Question: how does a person know if their /dev is a static or dynamic /dev > >> >> % findmnt /dev >> TARGET SOURCE FSTYPE OPTIONS >> /dev devtmpfs devtmpfs rw,size=249844k,nr_inodes=62461,mode=755 >> >> Unless you have taken very special steps to avoid it, you will >> always have a dynamic /dev. This has been the case for many >> many years now. udev uses a tmpfs mounted on /dev (and more >> recently a devtmpfs mounted on /dev). >> >> If there's nothing mounted on /dev, then you will have a static >> /dev. However, if using Linux, the chances of having a static >> /dev on a contemporary system are vanishingly small--you'd have >> to intentionally alter the boot scripts to avoid a dynamic /dev. >> > > What does it mean when /dev is said to be static? dynamic? > What should I be reading about?
Many years ago, /dev was a directory containing entries called "special files" (which essentially meant mappings from filenames to device drivers). It was the responsibility of the system administrator to make sure that any time a device was added, a corresponding special file was added to /dev. In such a system, /dev is static. In a modern system, /dev doesn't physically exist on disk at all: it's a special kind of filesystem that lives only in the memory of the computer, called a tmpfs (temporary filesystem). Daemons detect what hardware is available, and automatically create the right special files in this filesystem. This is a dynamic /dev. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1bvc80ty8b....@snowball.wb.pfeifferfamily.net
