Re: SCSI Tape Corruption - update 2

Re: SCSI Tape Corruption - update 2

[Nate Eldredge]

lomarcan@tin.it wrote:

> Well, the 2.2 distributed with Mandrake 7.2 works fine ... :) 
>
> Hmmm... 32 CONSECUTIVE bytes are a very peculiar error. What can it be? 
>
> Still experimenting...

I once ran into a problem with 32-byte errors appearing in files, and
later, in memory.  I eventually traced it to buggy motherboard cache.
(32 bytes is the size of a cache line.)  A memory tester might be
something to try (I wrote a simple program that seemed to show the
error better than memtest86; can send it if desired.)
 
-- 

Nate Eldredge
neldredge@hmc.edu

Re: SCSI Tape Corruption - update 2

[Geert Uytterhoeven]

On Fri, 13 Apr 2001, Nate Eldredge wrote:
> lomarcan@tin.it wrote:
> > Well, the 2.2 distributed with Mandrake 7.2 works fine ... :) 
> >
> > Hmmm... 32 CONSECUTIVE bytes are a very peculiar error. What can it be? 
> >
> > Still experimenting...
> 
> I once ran into a problem with 32-byte errors appearing in files, and
> later, in memory.  I eventually traced it to buggy motherboard cache.
> (32 bytes is the size of a cache line.)  A memory tester might be
> something to try (I wrote a simple program that seemed to show the
> error better than memtest86; can send it if desired.)

In that case I'd expect the problem to show up when doing whatever. So far I
could not find corrupted files on my hard disk, only when writing to tape, and
only with 2.3/2.4.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Re: SCSI Tape Corruption - update 2

[Lorenzo Marcantonio]

On Fri, 13 Apr 2001, Nate Eldredge wrote:

> (32 bytes is the size of a cache line.)  A memory tester might be
> something to try (I wrote a simple program that seemed to show the
> error better than memtest86; can send it if desired.)

Already tried that... this system has passed some 20 hours running
memtest86...

Also I've got NO OTHER memory failure symptom (and the tape fails only on
writing)

				-- Lorenzo Marcantonio

Re: SCSI Tape Corruption - update 2

[Chip Salzenberg]

In article <Pine.LNX.4.31.0104142043340.1271-100000@eris.discordia.loc> you write:
>On Fri, 13 Apr 2001, Nate Eldredge wrote:
>> (32 bytes is the size of a cache line.)  A memory tester might be
>> something to try (I wrote a simple program that seemed to show the
>> error better than memtest86; can send it if desired.)
>
>Already tried that... this system has passed some 20 hours running
>memtest86...

I suggest you try Cerberus:

  https://sourceforge.net/projects/va-ctcs/

which will viciously beat your system to within an inch of its life.
If you have any motherboard problems, they're more likely to show up
with Cerberus than with a simple memtest.
-- 
Chip Salzenberg              - a.k.a. -             <chip@valinux.com>
 "We have no fuel on board, plus or minus 8 kilograms."  -- NEAR tech

Re: SCSI Tape Corruption - update

[Gérard Roudier]

On Thu, 12 Apr 2001 lomarcan@tin.it wrote:

> Still experimenting with my SDT-9000... tried connecting it to another
> controller
> (2940AU in place of 2904, sorry but I've only Adaptec stuff :). Same
> problem.
> Tried with another tape (even with an old DDS-2 tape). Same. Even tried
> another
> cable/removing the CDWR drive from the bus.
> 
> It seems that the tape is written incorrectly. I wrote some large file
> (300MB)
> and read it back four time. The read copies are all the same. They differ
> from the original only in 32 consecutive bytes (the replaced values SEEM
> random). Of course, 32 bytes in 300MB tar.gz files are TOO MUCH to be 
> accepted :)

A similar problem has been reported under Linux/PPC a couple of weeks ago
using a sym53c875 controller. In this case, kernel 2.2 was fine.

> Now I'll build some old 2.2 kernel to try...

If 2.2 is ok with your tape, a software error in 2.4 gets very likely, in
my opinion.

  Gérard.

Re: SCSI Tape Corruption - update 2

[Lorenzo Marcantonio]

On Thu, 12 Apr 2001, Gérard Roudier wrote:

> using a sym53c875 controller. In this case, kernel 2.2 was fine.
>
> > Now I'll build some old 2.2 kernel to try...
>
> If 2.2 is ok with your tape, a software error in 2.4 gets very likely, in
> my opinion.

Well, the 2.2 distributed with Mandrake 7.2 works fine ... :)

Hmmm... 32 CONSECUTIVE bytes are a very peculiar error. What can it be?

Still experimenting...

				-- Lorenzo Marcantonio