Hi all

I have a problem where I need your help.

For a customer, I need to read a tape called MLR1-26GB from Imation. The 
tape comes from an iSeries in V5R4 format. It took a long time to rewind, so 
there should be a lot of data on it.

The drive I have for that purpose, is a Tandberg MLR3 (25-50GB). The 
software recognises the density as DC5010, but reports that no files have 
been found.

I have no problems reading a 2 gig tape on the same drive, so (most of) it 
is working.

Also, I cannot write a SLRtape24 (also from Imation) on the MLR3 drive; the 
software writes "cannot write on this medium".

Can anyone shed some light on this ? I've been looking various places on the 
'net, but been unable to find relevant information.

Thanks

Nico

Nico de Jong <nico@farumdata.dk> wrote:
> Hi all
> 
> I have a problem where I need your help.
> 
> For a customer, I need to read a tape called MLR1-26GB from Imation. The 
> tape comes from an iSeries in V5R4 format. It took a long time to rewind, so 
> there should be a lot of data on it. 

rewind time doesn't really mean anything with QIC tapes, they read and 
write in many full length passes unlike DLT.

> The drive I have for that purpose, is a Tandberg MLR3 (25-50GB). The 
> software recognises the density as DC5010, but reports that no files have 
> been found.
> 
> I have no problems reading a 2 gig tape on the same drive, so (most of) it 
> is working.
> 
> Also, I cannot write a SLRtape24 (also from Imation) on the MLR3 drive; the 
> software writes "cannot write on this medium".

what software and system are you using to try to read the tape?

"Cydrome Leader" <presence@MUNGEpanix.com> skrev i en meddelelse 
news:gl7lpp$ckg$1@reader1.panix.com...
>>
>> Also, I cannot write a SLRtape24 (also from Imation) on the MLR3 drive; 
>> the
>> software writes "cannot write on this medium".
>
> what software and system are you using to try to read the tape?

InterMedia from the UK (of which I am the Danish/Norwegian distributor).
The software can also take dumps and analyse blocklengths etc, but 
everything tells me immediately that it has reached end of tape.

I wonder whether the density (DC5010) is incompatible with my drive, but on 
the other hand, how could the drive then detect the density ?
I mailed Tandberg in the meantime, as I couldnt find their compatibility 
chart anymore

Nico 

Nico de Jong <nico@farumdata.dk> wrote:
> 
> "Cydrome Leader" <presence@MUNGEpanix.com> skrev i en meddelelse 
> news:gl7lpp$ckg$1@reader1.panix.com...
>>>
>>> Also, I cannot write a SLRtape24 (also from Imation) on the MLR3 drive; 
>>> the
>>> software writes "cannot write on this medium".
>>
>> what software and system are you using to try to read the tape?
> 
> InterMedia from the UK (of which I am the Danish/Norwegian distributor).
> The software can also take dumps and analyse blocklengths etc, but 
> everything tells me immediately that it has reached end of tape.
> 
> I wonder whether the density (DC5010) is incompatible with my drive, but on 
> the other hand, how could the drive then detect the density ?
> I mailed Tandberg in the meantime, as I couldnt find their compatibility 
> chart anymore

Hmm. Do you know what sort of drive wrote the tape you have? I don't have 
the compatibility table memorized anymore, but there is a weird overlap in 
how the tandberg drives worked. There was usually a 1 or 2 generation read 
capability for backwards compatbility, but it may be possible that the 
SLR24 tape was written on an older drive, and at a density too low for the 
newer MLR3 that you have.

As for SLR and MLR, they're the same. Older generation drives and tapes 
were called MLR and the newer ones SLR, or vice versa. There was no 
difference as long as the numbers matched. Some drives were sold under 
both names.

It sounds like your software is smart enough to use the correct device 
minor numbers. In unix, if you get this wrong, the tape drive will be in 
the wrong mode and unable to either read or write tapes written elsewhere.

Cydrome Leader <presence@MUNGEpanix.com> writes:
>Nico de Jong <nico@farumdata.dk> wrote:
>> 
>> "Cydrome Leader" <presence@MUNGEpanix.com> skrev i en meddelelse 
>> news:gl7lpp$ckg$1@reader1.panix.com...
>>>>
>>>> Also, I cannot write a SLRtape24 (also from Imation) on the MLR3 drive; 
>>>> the
>>>> software writes "cannot write on this medium".
>>>
>>> what software and system are you using to try to read the tape?
>> 
>> InterMedia from the UK (of which I am the Danish/Norwegian distributor).
>> The software can also take dumps and analyse blocklengths etc, but 
>> everything tells me immediately that it has reached end of tape.
>> 
>> I wonder whether the density (DC5010) is incompatible with my drive, but on 
>> the other hand, how could the drive then detect the density ?
>> I mailed Tandberg in the meantime, as I couldnt find their compatibility 
>> chart anymore
>
>Hmm. Do you know what sort of drive wrote the tape you have? I don't have 
>the compatibility table memorized anymore, but there is a weird overlap in 
>how the tandberg drives worked. There was usually a 1 or 2 generation read 
>capability for backwards compatbility, but it may be possible that the 
>SLR24 tape was written on an older drive, and at a density too low for the 
>newer MLR3 that you have.
>
>As for SLR and MLR, they're the same. Older generation drives and tapes 
>were called MLR and the newer ones SLR, or vice versa. There was no 
>difference as long as the numbers matched. Some drives were sold under 
>both names.
>
>It sounds like your software is smart enough to use the correct device 
>minor numbers. In unix, if you get this wrong, the tape drive will be in 
>the wrong mode and unable to either read or write tapes written elsewhere.

One key thing to keep in mind, particularly when reading with linux or
unix, is whether or not the tape was written with fixed or variable
length blocks.   Many mainframes, for example, would write using variable
length blocks and such tapes can't be read if the driver thinks it's reading
a fixed block size tape.   With linux, you can use the mt command to set the
tape drive blocksize to zero, then the tape can be read.

mt -f /dev/st0 status
mt -f /dev/st0 setblk 0

scott

"Cydrome Leader" <presence@MUNGEpanix.com> skrev i en meddelelse 
news:gl81r9$kbi$1@reader1.panix.com...
> Nico de Jong <nico@farumdata.dk> wrote:
>>
>> "Cydrome Leader" <presence@MUNGEpanix.com> skrev i en meddelelse
>> news:gl7lpp$ckg$1@reader1.panix.com...
>>>>
>>>> Also, I cannot write a SLRtape24 (also from Imation) on the MLR3 drive;
>>>> the
>>>> software writes "cannot write on this medium".
>>>
>>> what software and system are you using to try to read the tape?
>>
>> InterMedia from the UK (of which I am the Danish/Norwegian distributor).
>> The software can also take dumps and analyse blocklengths etc, but
>> everything tells me immediately that it has reached end of tape.
>>
>> I wonder whether the density (DC5010) is incompatible with my drive, but 
>> on
>> the other hand, how could the drive then detect the density ?
>> I mailed Tandberg in the meantime, as I couldnt find their compatibility
>> chart anymore
>
> Hmm. Do you know what sort of drive wrote the tape you have? I don't have
> the compatibility table memorized anymore, but there is a weird overlap in
> how the tandberg drives worked. There was usually a 1 or 2 generation read
> capability for backwards compatbility, but it may be possible that the
> SLR24 tape was written on an older drive, and at a density too low for the
> newer MLR3 that you have.
>
> As for SLR and MLR, they're the same. Older generation drives and tapes
> were called MLR and the newer ones SLR, or vice versa. There was no
> difference as long as the numbers matched. Some drives were sold under
> both names.
>
> It sounds like your software is smart enough to use the correct device
> minor numbers. In unix, if you get this wrong, the tape drive will be in
> the wrong mode and unable to either read or write tapes written elsewhere.

I'm not familiar with the iSeries, and the company went belly up, so that 
remains an open question.
I am familiar with the backwards compatibility issue. Normally 4-5x Read 
backward, and 2x Write backward.
I found the possible configurations at 
http:--www.nvcsales.com-IBM-iperipherals.asp (replade the - with /) but I 
have no crossreference between IBM part numbers and Tandberg QIC drives, so 
I'm still stuck.
The software I use, is Windows based, and I do not have access to unix 
systems

This kind of tape must no be bulk-erased, but what happens when it is? of 
course the servo thing goes wrong, but does that confuse the drive, or does 
it just say "no data" or "end of tape" or something like that?

Nico 

Nico de Jong wrote:
> 
> This kind of tape must no be bulk-erased, but what happens when it is? of
> course the servo thing goes wrong, but does that confuse the drive, or does
> it just say "no data" or "end of tape" or something like that?

No. To detect an EOT (end of tape) or EOD (end of data) mark the drive
must be able to read the medium. Without the servo data the drive cannot
access the medium at all and should report something like "Not
ready/Medium error".

And because the drive cannot write new servo data, the medium stay
unusable from that point. You can throw ist away.


Micha

On Thu, 22 Jan 2009 09:22:56 +0100, Nico de Jong wrote:

..... 
> I'm not familiar with the iSeries, and the company went belly up, so
> that remains an open question.
.....

The iSeries (AKA AS400) is manufactured by IBM.
They are still a going concern.

-- 
Jeremy

"Jeremy Boden" <jeremy@moiety.plus.com> skrev i en meddelelse 
news:xb2dnR1iDsRss-TUnZ2dnUVZ8svinZ2d@posted.plusnet...
> On Thu, 22 Jan 2009 09:22:56 +0100, Nico de Jong wrote:
>
> ....
>> I'm not familiar with the iSeries, and the company went belly up, so
>> that remains an open question.
> ....
>
> The iSeries (AKA AS400) is manufactured by IBM.
> They are still a going concern.
>
> -- 
> Jeremy
Sorry, bad phrasing from my side. I meant the company that USED the iSeries 
:-)

On Fri, 23 Jan 2009 08:43:07 +0100, Nico de Jong wrote:

> "Jeremy Boden" <jeremy@moiety.plus.com> skrev i en meddelelse
> news:xb2dnR1iDsRss-TUnZ2dnUVZ8svinZ2d@posted.plusnet...
>> On Thu, 22 Jan 2009 09:22:56 +0100, Nico de Jong wrote:
>>
>> ....
>>> I'm not familiar with the iSeries, and the company went belly up, so
>>> that remains an open question.
>> ....
>>
>> The iSeries (AKA AS400) is manufactured by IBM. They are still a going
>> concern.
>>
>> --
>> Jeremy
> Sorry, bad phrasing from my side. I meant the company that USED the
> iSeries :-)

I think you will find (even if you strip out the error correction codes 
etc) that you are left with something that *may not* be readable.

It was unusual to produce tapes in standard interchange format.

If it's a save/restore format you will see lots of authorisation/object/
library etc details. This will be as offsets into lists or even lists of 
lists!

Furthermore, the save/restore format has varied, dependent upon the 
release of software installed.
BTW It was always possible to produce a tape formated as an earlier 
release from a later release.

Good luck.

-- 
Jeremy

In article <49773ead$0$56790$edfadb0f@dtext02.news.tele.dk>, Nico de
Jong <nico@farumdata.dk> writes

Sorry for the delay in responding, this thread has only just appeared in
my newsreader.

>For a customer, I need to read a tape called MLR1-26GB from Imation. The 
>tape comes from an iSeries in V5R4 format.

So it's been written using Unix.  Do you know what was used to produce
the tape?  Was it one of the standard *nox utilities (tar, dump, cpio)
or something else?

You mention that you've not had any luck reading this tape on a Windows
system.  If it's been written using a *nix variant, that's what I would
use to try and read the contents.

-- 
(\__/)   
(='.'=)  Bunny says Windows 7 is Vi$ta reloaded.
(")_(")  http://imgs.xkcd.com/comics/windows_7.png

On Mon, 23 Feb 2009 18:46:43 +0100, Mike Tomlinson wrote:

> In article <49773ead$0$56790$edfadb0f@dtext02.news.tele.dk>, Nico de
> Jong <nico@farumdata.dk> writes
> 
> Sorry for the delay in responding, this thread has only just appeared in
> my newsreader.
> 
>>For a customer, I need to read a tape called MLR1-26GB from Imation. The
>>tape comes from an iSeries in V5R4 format.
> 
> So it's been written using Unix.  Do you know what was used to produce
> the tape?  Was it one of the standard *nox utilities (tar, dump, cpio)
> or something else?
> 
> You mention that you've not had any luck reading this tape on a Windows
> system.  If it's been written using a *nix variant, that's what I would
> use to try and read the contents.

It's not been written on a unix or a PC!
It was written on an AS400 - RS6000 might just possibly be worth looking 
at since it's similar hardware. 

-- 
Jeremy

In article <y_2dnYX3AOjDbz_UnZ2dnUVZ8sCdnZ2d@posted.plusnet>, Jeremy
Boden <jeremy@moiety.plus.com> writes

>It's not been written on a unix or a PC!
>It was written on an AS400

The OP said "V5R4 format".  I initially thought he was referring to BSD
System V release 4, but of course an IBM system would run AIX.

I see that V5R4 refers to a new release of i5/OS, which runs on AS/400,
now called System i.  A bit more digging shows that i5/OS saves data to
tape using a GO SAVE command, requiring the tape to be initialised
beforehand, and knowing IBM, the tape format is likely to be
proprietary.

Thanks for the correction.

-- 
(\__/)   
(='.'=)  Bunny says Windows 7 is Vi$ta reloaded.
(")_(")  http://imgs.xkcd.com/comics/windows_7.png

"Mike Tomlinson" <mike@jasper.org.uk> skrev i en meddelelse 
news:RxQnY$FIF2oJFwfE@jasper.org.uk...
> In article <y_2dnYX3AOjDbz_UnZ2dnUVZ8sCdnZ2d@posted.plusnet>, Jeremy
> Boden <jeremy@moiety.plus.com> writes
>
>>It's not been written on a unix or a PC!
>>It was written on an AS400
>
> The OP said "V5R4 format".  I initially thought he was referring to BSD
> System V release 4, but of course an IBM system would run AIX.
>
> I see that V5R4 refers to a new release of i5/OS, which runs on AS/400,
> now called System i.  A bit more digging shows that i5/OS saves data to
> tape using a GO SAVE command, requiring the tape to be initialised
> beforehand, and knowing IBM, the tape format is likely to be
> proprietary.
>
> Thanks for the correction.
>
Having found the correct Tandberg drive, I was able to read the tape on a 
Windows system.
However, it contained a physical dump of some database, but all relations, 
field descriptions etc. were not present, so I had to abandon the project.
Shit happens

Nico 

Jeremy Boden <jeremy@moiety.plus.com> writes:
>On Mon, 23 Feb 2009 18:46:43 +0100, Mike Tomlinson wrote:
>
>> In article <49773ead$0$56790$edfadb0f@dtext02.news.tele.dk>, Nico de
>> Jong <nico@farumdata.dk> writes
>> 
>> Sorry for the delay in responding, this thread has only just appeared in
>> my newsreader.
>> 
>>>For a customer, I need to read a tape called MLR1-26GB from Imation. The
>>>tape comes from an iSeries in V5R4 format.
>> 
>> So it's been written using Unix.  Do you know what was used to produce
>> the tape?  Was it one of the standard *nox utilities (tar, dump, cpio)
>> or something else?
>> 
>> You mention that you've not had any luck reading this tape on a Windows
>> system.  If it's been written using a *nix variant, that's what I would
>> use to try and read the contents.
>
>It's not been written on a unix or a PC!
>It was written on an AS400 - RS6000 might just possibly be worth looking 
>at since it's similar hardware. 
>

That means it was probably written with variable length blocks.  Most linux
and windows software expected fixed blocksize (512 bytes) on tape.  The
mt command can be used on linux to set to variable blocksize (this is usually
required to read tapes written by mainframes on linux).

scott