Re: (fwd) Bug#11922: I/O error on blank tapes

[Kai Makisara <Kai.Makisara@kolumbus.fi>]

On Mon, 4 Feb 2008, James Bottomley wrote:

> 
> On Mon, 2008-02-04 at 22:28 +0100, Borislav Petkov wrote:
> > On Mon, Feb 04, 2008 at 03:22:06PM +0100, maximilian attems wrote:
> > 
> > (Added Bart to CC)
> > 
> > > hello borislav,
> > > 
> > > may i forward you that *old* Debian kernel bug,
> > > have seen you working on ide-tape:
> > > http://bugs.debian.org/11922
> > > no we don't carry any ide patches anymore.
> > > 
> > > maybe you've already fixed it in latest?
> > > 
> > > thanks
> > > 
> > > -- 
> > > maks
> > > 
> > > ----- Forwarded message from Stephen Kitt <steve@sk2.org> -----
> > > 
> > > Subject: Bug#11922: I/O error on blank tapes
> > > Date: Sat, 1 Dec 2007 19:06:18 +0100
> > > From: Stephen Kitt <steve@sk2.org>
> > > To: 11922@bugs.debian.org
> > > 
> > > Hi,
> > > 
> > > This does still occur with 2.6.22; with a blank tape in my HP DDS-4 drive:
> > > 
> > > $ tar tzvf /dev/nst0
> > > tar: /dev/nst0: Cannot read: Input/output error
> 
> That's a SCSI tape, not an IDE one.  I cc'd the SCSI list
> 
This is not a bug, it is a feature. There is _nothing_ on the tape and if 
you try to read something, you get an error. The same thing applies to 
reading after the last filemark. Note that after writing a filemark at the 
beginning of the tape, the situation is different. Now there is a file and 
the normal EOF semantics apply although there still is no data.

I admit that the error return could be more descriptive but the st driver 
tries to be compatible with other Unices.

The behavior can be changed if Linux does not match other Unices. I don't 
remember if I have tested just this with other Unices. I will try to test 
this with Tru64 tomorrow. If anyone has data on other Unices, it would be 
helpful.

-- 
Kai