[Q] tar - Mode or device-type changed

[bso at acm.org (Bosco So)]

In the ongoing effort of figuring out how to resize partitions, I've been
playing with tar.  I tarred a whole partition (hda2) while using another
(hda3) as the root disk.  The resultant tar file was stored on yet another
partition (hda5).  When I compared the tar file with the content of the
original partition, I got the following messages.  Are these real errors? 
Or are they an artifact of the way Linux handles devices?  If so, then the
last two lines seem to be legitimate errors since /tmp and /var/tmp are
real directories.  Right?

dev/audio: Mode or device-type changed
dev/audio1: Mode or device-type changed
dev/dsp: Mode or device-type changed
dev/dsp1: Mode or device-type changed
dev/log: Mode or device-type changed
dev/midi00: Mode or device-type changed
dev/midi01: Mode or device-type changed
dev/midi02: Mode or device-type changed
dev/midi03: Mode or device-type changed
dev/mixer: Mode or device-type changed
dev/mixer1: Mode or device-type changed
dev/null: Mode or device-type changed
dev/ptyp0: Mode or device-type changed
dev/ptyp1: Mode or device-type changed
dev/ptyp2: Mode or device-type changed
dev/ptyp3: Mode or device-type changed
dev/ptyp4: Mode or device-type changed
dev/ptyp5: Mode or device-type changed
dev/ptyp6: Mode or device-type changed
dev/ptyp7: Mode or device-type changed
dev/ptyp8: Mode or device-type changed
dev/ptyp9: Mode or device-type changed
dev/ptypa: Mode or device-type changed
dev/ptypb: Mode or device-type changed
dev/ptypc: Mode or device-type changed
dev/ptypd: Mode or device-type changed
dev/ptype: Mode or device-type changed
dev/ptypf: Mode or device-type changed
dev/sequencer: Mode or device-type changed
dev/sndstat: Mode or device-type changed
dev/tty: Mode or device-type changed
dev/ttyp0: Mode or device-type changed
dev/ttyp1: Mode or device-type changed
dev/ttyp2: Mode or device-type changed
dev/ttyp3: Mode or device-type changed
dev/ttyp4: Mode or device-type changed
dev/ttyp5: Mode or device-type changed
dev/ttyp6: Mode or device-type changed
dev/ttyp7: Mode or device-type changed
dev/ttyp8: Mode or device-type changed
dev/ttyp9: Mode or device-type changed
dev/ttypa: Mode or device-type changed
dev/ttypb: Mode or device-type changed
dev/ttypc: Mode or device-type changed
dev/ttypd: Mode or device-type changed
dev/ttype: Mode or device-type changed
dev/ttypf: Mode or device-type changed
tmp: Mode differs
var/tmp: Mode differs