Can't read SCSI TAPE

Can't read SCSI TAPE

[Masaki Tsuji]

Dear sirs,

Although 'tar' can write to SCSI-TAPE, can't read from.
'tar' reports ....

......
-rw-r--r-- root/root    xxxxx 2001-xx-xx 01:23 usr/bin/xxxxxx
tar: Skipping to next file header                            <------"A"
-rw-r--r-- root/root    xxxxx 2001-xx-xx 01:23 usr/bin/xxxxxxx
......


"A" means written data is wrong, doesn't it???


Thanks for any help.

------------------------------------------
Detailed ->

System...
Kernel : 2.2.11 + raid0145-19990824-2.2.11.gz
          or
         2.2.11
tar    : GNU tar 1.12
mt     : mt-st v. 0.4
glibc2 : glibc-2.0.7pre6

Hardware...
Mother   : Intel Celeron x2 (SMP)
TAPE drv : SONY SDT-9000
TAPE     : DDS1 DDS2 DDS3
SCSI card: AHA-1542
Cable    : SCSI-2 Hi-impeadance , length 0.5m
------------------------------------------

-- 
Masaki Tsuji

Re: Can't read SCSI TAPE

[Richard B. Johnson]

On Wed, 25 Apr 2001, Masaki Tsuji wrote:

> Dear sirs,

Hmmm...

Masaki Tsuji <jammasa@ma.nma.ne.jp>
                      ^^^^^^^^^^^^ ____ This address

... was the address that did the CA-2000-17 attack on one of
our machines a few weeks ago.

This is not an accusation, only an observation. You might
want to tell your network administrator. Sombody at your
site may be hacking systems.

SCSI tape problems or your kind are usually caused by a different
tape compression being used during record and playback. You should
try to use `mt` to set the compression to something you like
before you record, and the same compression when you play back
the tape.

You can use `cat` and `od` to read/write from a tape before you
waste a lot file time with `tar`. You can even do:

		ls >/dev/tape
                 .... takes a lot of time..

		cat /dev/tape  # Read back.

Blocking/deblocking is done in the driver so you can treat it as
a "slow-to-start" FIFO.


Cheers,
Dick Johnson

Penguin : Linux version 2.4.1 on an i686 machine (799.53 BogoMips).

"Memory is like gasoline. You use it up when you are running. Of
course you get it all back when you reboot..."; Actual explanation
obtained from the Micro$oft help desk.

Re: Can't read SCSI TAPE

[Masaki Tsuji]

Dears,

"Richard B. Johnson" wrote:
> 
> Hmmm...
> 
> Masaki Tsuji <jammasa@ma.nma.ne.jp>
>                       ^^^^^^^^^^^^ ____ This address
> 
> ... was the address that did the CA-2000-17 attack on one of
> our machines a few weeks ago.
> 
> This is not an accusation, only an observation. You might
> want to tell your network administrator. Sombody at your
> site may be hacking systems.

We're very sorry!

Probabry it's 10th or 11th Apr, isn't it?
I was attacked too, but from outside.

I asked my network administrator about that on 13th Apr, and catched reason.
They said that their network equipments had some probrems, and fixed it.


> SCSI tape problems or your kind are usually caused by a different
> tape compression being used during record and playback. You should
> try to use `mt` to set the compression to something you like
> before you record, and the same compression when you play back
> the tape.

I tried compression option, but It doesn't work well.

I tried ...

No.1
# mt datcompression 1
... write
# mt datcompression 1
... read

No.2
# mt datcompression 0
... write
# mt datcompression 1
... read

No.3
# mt datcompression 1
... write
# mt datcompression 0
... read

No.4
# mt datcompression 0
... write
# mt datcompression 0
... read

, but can't

'datcompression' isn't correct option ?


> You can use `cat` and `od` to read/write from a tape before you
> waste a lot file time with `tar`. You can even do:
> 
>                 ls >/dev/tape
>                  .... takes a lot of time..
> 
>                 cat /dev/tape  # Read back.
> 
> Blocking/deblocking is done in the driver so you can treat it as
> a "slow-to-start" FIFO.

I tried, and got error message...

-----------------------------------
# ls >/dev/tape
st0: Write not multiple of tape block size.   <----- ???
ls: write error: Input/output error
#
-----------------------------------
# cat /dev/tape
[inclemental-] Tue Apr 24 03: ......          <----- looks like good!
#
-----------------------------------

Something wrong?



Thanks, for your help.

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-- 
Masaki Tsuji

Re: Can't read SCSI TAPE

[Tim Moore]

> mt     : mt-st v. 0.4

Also mt-st < v0.5b were fairly broken especially with positioning.

rgds,
tim.
--

Can't read SCSI TAPE

[Masaki Tsuji]

Dear sirs,

Although 'tar' can write to SCSI-TAPE, can't read from.
'tar' reports ....

......
-rw-r--r-- root/root    xxxxx 2001-xx-xx 01:23 usr/bin/xxxxxx
tar: Skipping to next file header                            <------"A"
-rw-r--r-- root/root    xxxxx 2001-xx-xx 01:23 usr/bin/xxxxxxx
......


"A" means written data is wrong, doesn't it???


Thanks for any help.

------------------------------------------
Detailed ->

System...
Kernel : 2.2.11 + raid0145-19990824-2.2.11.gz
          or
         2.2.11
tar    : GNU tar 1.12
mt     : mt-st v. 0.4
glibc2 : glibc-2.0.7pre6

Hardware...
Mother   : Intel Celeron x2 (SMP)
TAPE drv : SONY SDT-9000
TAPE     : DDS1 DDS2 DDS3
SCSI card: AHA-1542
Cable    : SCSI-2 Hi-impeadance , length 0.5m
------------------------------------------

-- 
Masaki Tsuji