Tar won't write to default devices

[Scott "The Pseudo-Hacker" Neugroschl]

Why can't I get tar(1) to work with the default devices?

Config:	Motorola Delta 3600 running System V/68 R3V5 (Motorola's V.3)
	Archive 2150S SCSI tape drive
	MVME141 CPU, MVME327 SCSI ctrlr
	Write Enabled DC600A tape
	^^^^^ ^^^^^^^

TFM states that the default devices for tar(1) are (in order) /dev/mt/0m
followd by /dev/mt0.  I don't like having a raw device under /dev/mt, so
I linked /dev/rmt/m327_40t to /dev/mt0.  The problem?

I can tar to /dev/rmt/m327_40t (tar cvf /dev/rmt/m327_40t files), I can
even explicitly tar to /dev/mt0 ok (tar cvf /dev/mt0 files), I can
tar FROM the default device ok (tar tv).  What I CAN'T do is tar _TO_
the default device (tar cv files).

When I try tarring to the default device I get:

tar: cannot open /dev/mt/0m, No such file or directory
tar: cannot open /dev/mt0, No such device or address

Now.  I can live with the first one, as /dev/mt/0m doesn't exist.  But
I cannot for the life of me figure out WHY I am getting the second error.
I can read the device using it as the default.  I can even WRITE the file
using it as the explictly named tar device.  WHY can't I write to it
as the default tar device?  And yes, my tape IS write enabled.

In other words:

$ tar tv
--- tar listing
$ tar xv
--- files extracted
$ tar cvf /dev/mt0 files
--- tarchive created on /dev/mt0
$ tar cv files
tar: cannot open /dev/mt/0m, No such file or directory
tar: cannot open /dev/mt0, No such device or address


aTdHvAaNnKcSe

Scott

Please send replies to ...!csun.edu!litvax!abctdev!scott
		or  to abcscnge at csuna.csun.edu



-- 
Scott "The Pseudo-Hacker" Neugroschl
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-- Beat me, Whip me, make me code in Ada
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