Re: Narrowing down problem source

From	Richard Owlett <rowlett@cloud85.net>
Newsgroups	linux.debian.user
Subject	Re: Narrowing down problem source
Date	2015-09-21 19:00 +0200
Message-ID	<qbcBz-43c-5@gated-at.bofh.it> (permalink)
References	<qaTpg-1Zo-17@gated-at.bofh.it> <qb2Cd-6Ly-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Thomas Schmitt wrote:
> Hi,
>
> Richard Owlett wrote:
>> Block count: 1941504
>> ...
>> 1941504+0 records in
>> 1941504+0 records out
>
> This is ok.
>
>> Block count: 2284052
>> ...
>> 1941504+0 records in
>> 1941504+0 records out
>
> This is not ok.
>
> The variable "block" was computed correctly, but program "dd"
> did not retrieve enough blocks.
> (I wonder whether it's a bug or a feature that it does not
>   report an error. At least this behavior is reproducible.)
>
> It seems that the system does not tell "dd" the block count of
> the new DVD but the count of the previous one.
>
> What do you get from this command
>
>    echo "Device block count: $(expr $(cat /sys/class/block/sr0/size) / 4)"
>
> inserted in the script after the line
>    echo "Byte count: $(expr $blocks '*' 2048)"
>
> (The /sys filesystem is an inexhaustible source of wonders.)
>

"Device block count" <> "blocks"
HOWEVER, resulting *.iso for DVD1 and DVD2 are the same size even 
though input sizes were different.

Output of script command below:

Script started on Mon 21 Sep 2015 08:44:20 AM CDT

N=0

F="JessieDVD"

E='.iso'

while true

   do

     let N=N+1

      echo "Insert medium, wait until blinking ends, press Enter 
key (or Ctrl+C to end)"

     read dummyvar

     blocks=$(expr $(/sbin/isosize /dev/sr0) / 2048)

     echo "Block count: "$blocks

     echo "Byte count: $(expr $blocks '*' 2048)"

DEVICEBLKCOUNT=$(expr $(cat /sys/class/block/sr0/size) / 4)

     echo "Device block count: "$DEVICEBLKCOUNT

     FILENAME=$F$N$E

     echo "The output file will be $FILENAME"

     echo ""

     dd if=/dev/sr0 bs=2048 count=$DEVICEBLKCOUNT of=$FILENAME

     echo ""

     echo "next lines are output of ls and isosize commnds"

     ls -l $FILENAME

     /sbin/isosize $FILENAME

     echo "about to repeat loop"

     echo ""

   done

]0;richard@debian-8: ~richard@debian-8:~$
]0;richard@debian-8: ~richard@debian-8:~$ N=0
]0;richard@debian-8: ~richard@debian-8:~$
]0;richard@debian-8: ~richard@debian-8:~$ F="JessieDVD"
]0;richard@debian-8: ~richard@debian-8:~$
]0;richard@debian-8: ~richard@debian-8:~$ E='.iso'
]0;richard@debian-8: ~richard@debian-8:~$
]0;richard@debian-8: ~richard@debian-8:~$ while true
>
>   do
>
>     let N=N+1
>
>      echo "Insert medium, wait until blinking ends, press Enter key (or Ctrl+C
  to end)"
>
>     read dummyvar
>
>     blocks=$(expr $(/sbin/isosize /dev/sr0) / 2048)
>
>     echo "Block count: "$blocks
>
>     echo "Byte count: $(expr $blocks '*' 2048)"
>
> DEVICEBLKCOUNT=$(expr $(cat /sys/class/block/sr0/size) / 4)
>
>     echo "Device block count: "$DEVICEBLKCOUNT
>
>     FILENAME=$F$N$E
>
>     echo "The output file will be $FILENAME"
>
>     echo ""
>
>     dd if=/dev/sr0 bs=2048 count=$DEVICEBLKCOUNT of=$FILENAME
>
>     echo ""
>
>     echo "next lines are output of ls and isosize commnds"
>
>     ls -l $FILENAME
>
>     /sbin/isosize $FILENAME
>
>     echo "about to repeat loop"
>
>     echo ""
>
>   done
Insert medium, wait until blinking ends, press Enter key (or 
Ctrl+C to end)
Block count: 1941504
Byte count: 3976200192
Device block count: 1941504
The output file will be JessieDVD1.iso

1941504+0 records in
1941504+0 records out
3976200192 bytes (4.0 GB) copied, 762.909 s, 5.2 MB/s

next lines are output of ls and isosize commnds
-rw-r--r-- 1 richard richard 3976200192 Sep 21 08:57 JessieDVD1.iso
3976200192
about to repeat loop

Insert medium, wait until blinking ends, press Enter key (or 
Ctrl+C to end)

Block count: 2284052
Byte count: 4677738496
Device block count: 2284064
The output file will be JessieDVD2.iso

1941504+0 records in
1941504+0 records out
3976200192 bytes (4.0 GB) copied, 2655.4 s, 1.5 MB/s

next lines are output of ls and isosize commnds
-rw-r--r-- 1 richard richard 3976200192 Sep 21 09:43 JessieDVD2.iso
4677738496
about to repeat loop

Insert medium, wait until blinking ends, press Enter key (or 
Ctrl+C to end)
^C
]0;richard@debian-8: ~richard@debian-8:~$ exit

Script done on Mon 21 Sep 2015 09:43:50 AM CDT

Thread

Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-10 15:10 +0200
  Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-10 15:20 +0200
    Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-10 16:10 +0200
      Re: Extracting directories from an ISO image, command line tool? The Wanderer <wanderer@fastmail.fm> - 2015-09-10 16:30 +0200
        Re: Extracting directories from an ISO image, command line tool? The Wanderer <wanderer@fastmail.fm> - 2015-09-10 16:30 +0200
      Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-10 17:00 +0200
        Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-10 17:20 +0200
          Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-10 18:20 +0200
            Re: Extracting directories from an ISO image, command line tool? Hans <hans.ullrich@loop.de> - 2015-09-10 18:30 +0200
              Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-10 20:50 +0200
                Re: Extracting directories from an ISO image, command line tool? Hans <hans.ullrich@loop.de> - 2015-09-10 21:10 +0200
                Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-10 21:30 +0200
                Re: Extracting directories from an ISO image, command line tool? Curt <curty@free.fr> - 2015-09-10 22:10 +0200
                Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-10 23:00 +0200
                Re: Extracting directories from an ISO image, command line tool? Lisi Reisz <lisi.reisz@gmail.com> - 2015-09-11 15:40 +0200
                Re: Extracting directories from an ISO image, command line tool? Chris Bannister <cbannister@slingshot.co.nz> - 2015-09-11 16:50 +0200
          Re: Extracting directories from an ISO image, command line tool? Lisi Reisz <lisi.reisz@gmail.com> - 2015-09-11 15:40 +0200
  Re: Extracting directories from an ISO image, command line tool? The Wanderer <wanderer@fastmail.fm> - 2015-09-10 15:30 +0200
    Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-10 16:20 +0200
      Re: Extracting directories from an ISO image, command line tool? The Wanderer <wanderer@fastmail.fm> - 2015-09-10 16:30 +0200
        Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-10 17:40 +0200
          Re: Extracting directories from an ISO image, command line tool? The Wanderer <wanderer@fastmail.fm> - 2015-09-10 17:50 +0200
      Re: Extracting directories from an ISO image, command line tool? Eduard Bloch <edi@gmx.de> - 2015-09-10 16:30 +0200
  Re: Extracting directories from an ISO image, command line tool? Darac Marjal <mailinglist@darac.org.uk> - 2015-09-10 15:30 +0200
    Re: Extracting directories from an ISO image, command line tool? The Wanderer <wanderer@fastmail.fm> - 2015-09-10 16:30 +0200
    Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-10 16:30 +0200
  Re: Extracting directories from an ISO image, command line tool? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-10 16:40 +0200
    Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-10 17:30 +0200
    Re: Extracting directories from an ISO image, command line tool? David Wright <deblis@lionunicorn.co.uk> - 2015-09-10 22:50 +0200
      Re: Extracting directories from an ISO image, command line tool? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-11 10:30 +0200
        Re: Extracting directories from an ISO image, command line tool? David Wright <deblis@lionunicorn.co.uk> - 2015-09-11 18:50 +0200
          Re: Extracting directories from an ISO image, command line tool? Curt <curty@free.fr> - 2015-09-12 10:10 +0200
          Re: Extracting directories from an ISO image, command line tool? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-12 11:00 +0200
    Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-13 23:20 +0200
      Re: Extracting directories from an ISO image, command line tool? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-14 00:40 +0200
        Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-14 03:00 +0200
          Re: Extracting directories from an ISO image, command line tool? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-14 10:20 +0200
            Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-14 16:40 +0200
              Narrowing down problem source - was [Re: Extracting directories from  an ISO image, command line tool?] Richard Owlett <rowlett@cloud85.net> - 2015-09-17 17:00 +0200
                Re: Narrowing down problem source - was [Re: Extracting directories from  an ISO image, command line tool?] Steve McIntyre <steve@einval.com> - 2015-09-17 18:10 +0200
                Re: Narrowing down problem source - was [Re: Extracting directories  from an ISO image, command line tool?] Richard Owlett <rowlett@cloud85.net> - 2015-09-18 13:20 +0200
                Re: Narrowing down problem source "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-17 19:20 +0200
                Re: Narrowing down problem source Richard Owlett <rowlett@cloud85.net> - 2015-09-18 14:40 +0200
                Re: Narrowing down problem source "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-18 15:00 +0200
                Re: Narrowing down problem source Richard Owlett <rowlett@cloud85.net> - 2015-09-18 15:40 +0200
                Re: Narrowing down problem source "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-18 15:50 +0200
                Re: Narrowing down problem source Richard Owlett <rowlett@cloud85.net> - 2015-09-20 22:30 +0200
                Re: Narrowing down problem source "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-21 08:20 +0200
                Re: Narrowing down problem source Richard Owlett <rowlett@cloud85.net> - 2015-09-21 19:00 +0200
                Re: Narrowing down problem source "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-21 20:30 +0200
  Re: Extracting directories from an ISO image, command line tool? David Wright <deblis@lionunicorn.co.uk> - 2015-09-10 17:10 +0200
    Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-10 19:40 +0200
  Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-11 14:10 +0200
    Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-11 17:40 +0200
      Re: Extracting directories from an ISO image, command line tool? Brian <ad44@cityscape.co.uk> - 2015-09-11 18:50 +0200
  Re: Extracting directories from an ISO image, command line tool? Stuart Longland <stuartl@longlandclan.id.au> - 2015-09-17 22:50 +0200
    Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-18 14:00 +0200
      Re: Extracting directories from an ISO image, command line tool? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-18 14:30 +0200
        Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-18 15:50 +0200
      Re: Extracting directories from an ISO image, command line tool? Stuart Longland <stuartl@longlandclan.id.au> - 2015-09-23 04:30 +0200
        Re: Extracting directories from an ISO image, command line tool? Richard Owlett <rowlett@cloud85.net> - 2015-09-23 16:00 +0200
          Re: Extracting directories from an ISO image, command line tool? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-09-23 20:10 +0200

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