Pls help : tape to tape backup (re-sent)

Pls help : tape to tape backup (re-sent)

Post by S.T. Wo » Fri, 05 Jan 1996 04:00:00



hi, there,

Would anyone pls advise if there's any hardware/software for duplicating tape
(DAT,  ExaByte, etc.) which contains data of different formats  (e.g. dump, tar,
OmniBackII of HP-UX, Networker, etc.) ?


Regards,
ST

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Pls help : tape to tape backup (re-sent)

Post by Andreas Kle » Fri, 05 Jan 1996 04:00:00




>hi, there,

>Would anyone pls advise if there's any hardware/software for duplicating tape
>(DAT,  ExaByte, etc.) which contains data of different formats  (e.g. dump, tar,
>OmniBackII of HP-UX, Networker, etc.) ?



man dd

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Pls help : tape to tape backup (re-sent)

Post by Edy Gasparin » Fri, 05 Jan 1996 04:00:00



> hi, there,

> Would anyone pls advise if there's any hardware/software for duplicating tape
> (DAT,  ExaByte, etc.) which contains data of different formats  (e.g. dump, tar,
> OmniBackII of HP-UX, Networker, etc.) ?

You can use the standard Unix dd command to perform tape to tape copying. I've done
this with archives of various formats (dump, tar, cpio) but not the others you mention.

The great thing about dd is, that you can use it together with rsh to copy from a tape
on one system to a tape on another system (and the tapes don't even have to be the same
type).

eg.

% dd if=localtape | rsh remotehost dd of=remotetape

cheers,
--
Edy Gasparini (... the thing I miss most is my mind)
-------------------------------------------------------------------
UNIX/PC Technical Support             Phone:     +61 (0)3 9301 1366
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--------------------cut here to destroy monitor--------------------

 
 
 

Pls help : tape to tape backup (re-sent)

Post by Zoran Cakelj » Tue, 09 Jan 1996 04:00:00




: >hi, there,
: >
: >Would anyone pls advise if there's any hardware/software for duplicating tape
: >(DAT,  ExaByte, etc.) which contains data of different formats  (e.g. dump, tar,
: >OmniBackII of HP-UX, Networker, etc.) ?
: >

: man dd

        1. dd won't work if there are file marks on the tape. You would have to
                work around them. dd will work for tar/dump/cpio formats.

        2. OmniBack II does provide a utility to duplicate a tape.

        Zoran

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Pls help : tape to tape backup (re-sent)

Post by Jeremy Le » Tue, 09 Jan 1996 04:00:00


Try tcopy if it is on your system.

Otherwise dd will work if you use a non-rewinding device and keep doing
dd onto a disk until a zero length archive is created, then you can dd
(in the same order) onto a new tape. You MUST use a non-rewinding device.

When doing this to/from helical tape drives, I think you have to use the
correct block size for each archive - this information is somehow obtainable
from the source media - but I am not sure how.

--
----------------------------------------------------------------------
Jeremy Lee
Wang Australia

 
 
 

Pls help : tape to tape backup (re-sent)

Post by Tye McQue » Thu, 11 Jan 1996 04:00:00


Quote:Jeremy Lee <jeremyl> writes:

) Try tcopy if it is on your system.
)
) Otherwise dd will work if you use a non-rewinding device and keep doing
) dd onto a disk until a zero length archive is created, then you can dd
) (in the same order) onto a new tape. You MUST use a non-rewinding device.
)
) When doing this to/from helical tape drives, I think you have to use the
) correct block size for each archive - this information is somehow obtainable
) from the source media - but I am not sure how.

On good old big slow 9-track tapes (watch an old episode of Hawaii
Five-O that has computers in it if you've never seen one), the
record size tells where to put the "inter-record gap" (or "end of
record mark") which really is a gap of some ridiculous size like
1/4" where no data is recorded.  I'm pretty sure the tape drive
uses this to be able to figure out were it is, kinda like the
sector marks on your standard (soft-sectored) floppy diskettes.

The practical outcomes of this are that all I/O to the tape drive
has to be done a full record at a time and that using a small
record size wastes a *lot* of space so that you can't fit as much
on the same length of tape.

Because helical-scan tapes exhibit these same behaviors, I assume
that their end of record marks are also real gaps.  I think they
are different from 9-track tapes in that 9-track tapes store data
as 9 horizontal rows of bits lines up together so that the record
size has to be an even number of bytes (with a 9th bit for parity)
while helical-scan tapes use diagonal stripes of bits that require
the record size to be a multiple of 512 bytes, for example.

Anyone got a nice picture of a strip of helical-scan tape media
showing precisely how the bits get lined up in 512-byte groups
and the shape/size of the inter-record gap?

) Jeremy Lee
) Wang Australia

--

             Nothing is obvious unless you are overlooking something
       http://www.metronet.com/~tye/ (scripts, links, nothing fancy)

 
 
 

Pls help : tape to tape backup (re-sent)

Post by S.T. Wo » Thu, 11 Jan 1996 04:00:00


hi, there,

Thanks to all who responded to my question:







Jeremy Lee <jeremyl>

As mentioned in mail received, "dd" can't handle *all* kind of backup tape.
Anyway, different software provide their way to copy tapes of their format.

Thanks a lot !

Cheers,
ST

------------------------------------ cut here ------------------------------
Original posting:

: Would anyone pls advise if there's any hardware/software for duplicating tape
: (DAT,  ExaByte, etc.) which contains data of different formats  (e.g. dump, tar,
: OmniBackII of HP-UX, Networker, etc.) ?

Summary:
----------------------------------------------------------------------------

Hi,

On my Sun there's a utility called 'tcopy' which will copy any tape to any
tape.
I'm not sure if the HP has it as well, since my HP disk just crashed....

Gerdjan.

----------------------------------------------------------------------------

I know that Andataco has a dual Exabyte unit that has various modes, such as
mirroring(making two copies simultaneously), cascading(fill up first tape and
continue on second automatically), and offline copy.

I believe the offline copy mode will do what you want, i.e. it does a raw copy
of the tape without regard to the storage format.

They probably have a dual DAT that will do the same thing.

Descriptions of their products can be found under their home page:

 http://www.andataco.com/

Regards,

George

----------------------------------------------------------------------------

man dd

--


                             \/
       ftp://sunsite.unc.edu/pub/Linux/system/Printing/aps-491.tgz
apsfilter - magic print filter 4lpd  >>> knobel is powered by FreeBSD <<<

----------------------------------------------------------------------------

You can use the standard Unix dd command to perform tape to tape copying. I've done
this with archives of various formats (dump, tar, cpio) but not the others you mention.

The great thing about dd is, that you can use it together with rsh to copy from a tape
on one system to a tape on another system (and the tapes don't even have to be the same
type).

eg.

% dd if=localtape | rsh remotehost dd of=remotetape

cheers,
--
Edy Gasparini (... the thing I miss most is my mind)
-------------------------------------------------------------------
UNIX/PC Technical Support             Phone:     +61 (0)3 9301 1366
Ericsson Data Australia              Mobile:     +61 (0)414 916 632
61 Riggall Street                       Fax:     +61 (0)3 9301 1085

--------------------cut here to destroy monitor--------------------

----------------------------------------------------------------------------

--
OBII tapes can be copied using omnicp. This utility is provide with OBII.
dd will not work with OBII.

Quote:> does omnicp only handle OBII tapes ?  

Yes.

------------------------------------------------------------------------------

-       HPDESK:         Peter NIEDERMANN /HPGRMY/UM   NSMD print&storage     -
-                                                     Building 3             -
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-       Fax:            ..49-7031-14-7481             Germany                -
------------------------------------------------------------------------------

----------------------------------------------------------------------------




: >hi, there,
: >
: >Would anyone pls advise if there's any hardware/software for duplicating tape
: >(DAT,  ExaByte, etc.) which contains data of different formats  (e.g. dump, tar,
: >OmniBackII of HP-UX, Networker, etc.) ?
: >

: man dd

        1. dd won't work if there are file marks on the tape. You would have to
                work around them. dd will work for tar/dump/cpio formats.

        2. OmniBack II does provide a utility to duplicate a tape.

        Zoran

--
 . ____ ___ __ __ ___* ......................................................

 *___/_//_/_/|_|_//_/      Vox: +386 (61) 1405004,  Fax: +386 (61) 1405070

----------------------------------------------------------------------------
From: Jeremy Lee <jeremyl>

Try tcopy if it is on your system.

Otherwise dd will work if you use a non-rewinding device and keep doing
dd onto a disk until a zero length archive is created, then you can dd
(in the same order) onto a new tape. You MUST use a non-rewinding device.

When doing this to/from helical tape drives, I think you have to use the
correct block size for each archive - this information is somehow obtainable
from the source media - but I am not sure how.

--
Jeremy Lee
Wang Australia

----------------------------------------------------------------------------

Dallastone markets and supports a full line of Unix backup, archiving and
library management software.  Included in the product suite are tape
duplication workstations and software packages for helical scan as well as
well as DLT.

If you need more info give us a reply!

Dallastone, Inc.

DALLASTONE, INCORPORATED
2 Cote Lane
Bedford, New Hampshire 03229
603-647-8168  (Fax) 603-624-2466

http://www.dallastone.com/dallastone (after Jan.1, 1996)
----------------------------------------------------------------------------
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Pls help : tape to tape backup (re-sent)

Post by Robert Upto » Fri, 12 Jan 1996 04:00:00



>On good old big slow 9-track tapes (watch an old episode of Hawaii
>Five-O that has computers in it if you've never seen one), the
>record size tells where to put the "inter-record gap" (or "end of
>record mark") which really is a gap of some ridiculous size like
>1/4" where no data is recorded.  I'm pretty sure the tape drive
>uses this to be able to figure out were it is, kinda like the
>sector marks on your standard (soft-sectored) floppy diskettes.

>The practical outcomes of this are that all I/O to the tape drive
>has to be done a full record at a time and that using a small
>record size wastes a *lot* of space so that you can't fit as much
>on the same length of tape.

>Because helical-scan tapes exhibit these same behaviors, I assume
>that their end of record marks are also real gaps.  I think they
>are different from 9-track tapes in that 9-track tapes store data
>as 9 horizontal rows of bits lines up together so that the record
>size has to be an even number of bytes (with a 9th bit for parity)
>while helical-scan tapes use diagonal stripes of bits that require
>the record size to be a multiple of 512 bytes, for example.

>Anyone got a nice picture of a strip of helical-scan tape media
>showing precisely how the bits get lined up in 512-byte groups
>and the shape/size of the inter-record gap?

Helical scan tapes write physical tracks across the tape at an angle.
Each one of these tracks are made up of a number of physical records
plus a fast tape search mark. Each physical record is made up of
header information, data, CRCand ECC error correcting code data.  
For instance on an Exabyte 8500 tape, there are 8 physical records
per track, and each physical record contains 14 bytes of header
information, 1K bytes of data, 2 bytes of CRC and 400 bytes of
ECC error correcting code.

Logical records may be be from 0 to 240 KB in length.  Logical records
may start anywhere in a physical block and span physical blocks.  There
are now IRG (inter-record gaps) like in 9 track tapes.  The IRG was a
means of correctly positioning the 9 track tape.  The helical scan tapes
have a linearly recorded track on one edge of the tape that is used to
position the tape accurately.  There is a special read head that is used
to position the tape.  Filemarks do take up space.  A short filemark
uses 1KB and a long filemark takes 48KB on 8mm tapes.

The only time that you lose capacity on these tapes is when you are
streaming data to the tape at less then the maximium capacity of the
tape drive.  In order to keep the tape moving, null data is sent to
the tape.  The reason for doing this, is to keep the tape moving.  
Stopping, repositioning and starting tape movement takes 8 seconds on
an 8mm tape.  Therefore, it is important to keep the tape moving.

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Pls help : tape to tape backup (re-sent)

Post by William Dei » Sat, 13 Jan 1996 04:00:00


 >Would anyone pls advise if there's any hardware/software for duplicating tape
 >(DAT,  ExaByte, etc.) which contains data of different formats  (e.g. dump, tar,
 >OmniBackII of HP-UX, Networker, etc.) ?

First, regarding the suggestion to use dd:  you can only use dd if you
do NOT pass the data through a pipe, because doing so will lose the
record size information.  You also must not use the dd option obs=nnn,
but rather simply  bs=nnn.  A few versions of dd will handle multiple
files, but usually you have to issue one call to dd to process each
file.

Some previous poster mentioned "tcopy".  I don't know about this program,
but thought I'd add mention of two other programs that are known to work:

    - David Hayes wrote "copytape", which you can find in various
    archives, for example
        ftp.cs.umn.edu:/pub/usenet/comp.sources.unix/volume10/copytape.Z

    - I have written "duptape", which uses familiar rcp-like syntax,
    and copies one or more files from one tape to another, preserving
    record lengths and filemarks.  The tape drives can reside on
    different machines.  Alternatively, you can copy from tape to disk and
    later back to tape.

    Example: copy local tape to remote tape, using a 64 KB copy buffer:

    You can get it from
        ftp.nfra.nl:pub/outgoing/will/duptape.shar
    or
        astro.caltech.edu:users/will/duptape.shar

-Will

 
 
 

1. WangDAT 2Gb backup, after 250Mb to tape message "END off TAPE" ??

Hi there,

Thanks for reading.

I try to backup my Linux system to a WangDAT 3200 4mm DAT unit.
After about 250Mb I get the message end of tape reached.

The unit is connected to a Adaptec 1542CF SCSI interface with SCSI-ID 6.

I use the device /dev/st0 and /dev/nst0 created with mknod c 9 0 and mknod c 9
128.

Can any body tell me if there is a solusion for this problem.

The only thing I haven't try'd is disabling compression because then the
unit only will backup 1Gb

Thanks in advance Jan H. van Gils

--
 ___________________________________________________________________
 Jan H. van Gils               |  http://www.knoware.nl/users/janvg/

                               |  Markpoort 5 4844 DA Terheijden
 -------------------------------------------------------------------

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