Re: gzip/zlib rsyncable (was: Accessibility of official jigdo filesfor Sarge)

2003-08-01 Thread Conny Brunnkvist
Richard Atterer wrote:
On Thu, Jul 31, 2003 at 08:35:11PM +0200, Conny Brunnkvist wrote:

--rsyncable   Make rsync-friendly archive

Hm, is this feature also somehow available in the Debian zlib packages? 
jigdo-file uses zlib to compress the .template files...
I understand that "rsyncable" is the result of a patch to gzip 
originally made by Rusty Russell. It seems to work, and I assume that it 
is being included upstream by now - details in:
http://pserver.samba.org/cgi-bin/cvsweb/rsync/patches/gzip-rsyncable.diff?rev=1.1

After a quick search I found the following posting from debian-devel, 
which elaborates a bit on both the effects as well as the status of the 
corresponding patch for zlib:
http://lists.debian.org/debian-devel/2003/debian-devel-200307/msg00462.html

So I guess(?) it's not in zlib yet, but it will be at some point.

//conny

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Can't mount burned Sarge - unknown type

2003-08-01 Thread Jere McDevitt
I used jigdo and created the sarge-i386.1 iso.  Doing a loop back mount
on the ISO everything is fine.  I burned the CD using the command listed
in the FAQ:

  nice --18 cdrecord -v speed=24 dev=1,0,0 -data -pad sarge.iso

Everything seemed ok, but when I mounted the burned CD I get the
standard "unknow filesystem, bad block," etc error.  I notice that the
FAQ command line didn't include either the -J or the -r flag.  Should
these have been necessary or would the iso9660 base been sufficient?
I'll try later with a new blank CD (and drop the burn speed down), but I
was curious about not seeing either flag.  For the record, the burner
worked fine for a 450 meg file that I built to backup important
information and that CD mounted fine.  

Thanks!

Jere
-- 
The sound we heard wasn't the bubble bursting, it was the big bang.
Rob Carter, CIO FedEx


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Re: Can't mount burned Sarge - unknown type

2003-08-01 Thread Greg Madden
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

On Friday 01 August 2003 04:59 am, Jere McDevitt wrote:
> I used jigdo and created the sarge-i386.1 iso.  Doing a loop back
> mount on the ISO everything is fine.  I burned the CD using the
> command listed in the FAQ:
>
>   nice --18 cdrecord -v speed=24 dev=1,0,0 -data -pad sarge.iso
>
> Everything seemed ok, but when I mounted the burned CD I get the
> standard "unknow filesystem, bad block," etc error.  I notice that
> the FAQ command line didn't include either the -J or the -r flag. 
> Should these have been necessary or would the iso9660 base been
> sufficient? I'll try later with a new blank CD (and drop the burn
> speed down), but I was curious about not seeing either flag.  For the
> record, the burner worked fine for a 450 meg file that I built to
> backup important information and that CD mounted fine.
>
> Thanks!
>
> Jere

cdrecord -v -eject dev=1,0,0 sarge.iso is what I use, I don't know about 
the additional options you used, though cdrocord seems to not have to 
have speed= specified, it reads the data from my disks.

- -- 
Greg Madden
Debian GNU/Linux
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Re: Accessibility of official jigdo files for Sarge

2003-08-01 Thread Richard Atterer
On Thu, Jul 31, 2003 at 09:26:52PM +0200, Richard Atterer wrote:
> Hm, is this feature also somehow available in the Debian zlib packages? 
> jigdo-file uses zlib to compress the .template files...

Hm, it just occurred to me that it might be possible for me to allow
rsyncability for .template files even without a patched zlib!

The gzip patch works by calculating a rolling checksum for the last n bytes
of the _un_compressed data. Whenever the checksum reaches a magic value
(0), the compress stream is flushed. This ensures that the flushing always
takes place at the same positions, just after the same data patterns.

With my knowledge about the .template files, I can do a similar (possibly
even better) thing: The compressed part of the .template consists of chunks
of image data which were not matched by any .deb in the Debian mirror.
Flushing between writing those chunks will do the trick.

To prevent this from affecting the compression ratio too much, it mustn't
happen too often, but current versions of jigdo-file already flush the
stream from time to time for other reasons, so it should be possible to
just move the "boundary" of the flush in an rsync-friendly way.

Cheers,

  Richard

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Re: gzip/zlib rsyncable (was: Accessibility of official jigdo files for Sarge)

2003-08-01 Thread Conny Brunnkvist
Richard Atterer wrote:
On Thu, Jul 31, 2003 at 08:35:11PM +0200, Conny Brunnkvist wrote:
--rsyncable   Make rsync-friendly archive
Hm, is this feature also somehow available in the Debian zlib packages? 
jigdo-file uses zlib to compress the .template files...
I understand that "rsyncable" is the result of a patch to gzip 
originally made by Rusty Russell. It seems to work, and I assume that it 
is being included upstream by now - details in:
http://pserver.samba.org/cgi-bin/cvsweb/rsync/patches/gzip-rsyncable.diff?rev=1.1

After a quick search I found the following posting from debian-devel, 
which elaborates a bit on both the effects as well as the status of the 
corresponding patch for zlib:
http://lists.debian.org/debian-devel/2003/debian-devel-200307/msg00462.html

So I guess(?) it's not in zlib yet, but it will be at some point.
//conny



Can't mount burned Sarge - unknown type

2003-08-01 Thread Jere McDevitt
I used jigdo and created the sarge-i386.1 iso.  Doing a loop back mount
on the ISO everything is fine.  I burned the CD using the command listed
in the FAQ:

  nice --18 cdrecord -v speed=24 dev=1,0,0 -data -pad sarge.iso

Everything seemed ok, but when I mounted the burned CD I get the
standard "unknow filesystem, bad block," etc error.  I notice that the
FAQ command line didn't include either the -J or the -r flag.  Should
these have been necessary or would the iso9660 base been sufficient?
I'll try later with a new blank CD (and drop the burn speed down), but I
was curious about not seeing either flag.  For the record, the burner
worked fine for a 450 meg file that I built to backup important
information and that CD mounted fine.  

Thanks!

Jere
-- 
The sound we heard wasn't the bubble bursting, it was the big bang.
Rob Carter, CIO FedEx




Re: Can't mount burned Sarge - unknown type

2003-08-01 Thread Greg Madden
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

On Friday 01 August 2003 04:59 am, Jere McDevitt wrote:
> I used jigdo and created the sarge-i386.1 iso.  Doing a loop back
> mount on the ISO everything is fine.  I burned the CD using the
> command listed in the FAQ:
>
>   nice --18 cdrecord -v speed=24 dev=1,0,0 -data -pad sarge.iso
>
> Everything seemed ok, but when I mounted the burned CD I get the
> standard "unknow filesystem, bad block," etc error.  I notice that
> the FAQ command line didn't include either the -J or the -r flag. 
> Should these have been necessary or would the iso9660 base been
> sufficient? I'll try later with a new blank CD (and drop the burn
> speed down), but I was curious about not seeing either flag.  For the
> record, the burner worked fine for a 450 meg file that I built to
> backup important information and that CD mounted fine.
>
> Thanks!
>
> Jere

cdrecord -v -eject dev=1,0,0 sarge.iso is what I use, I don't know about 
the additional options you used, though cdrocord seems to not have to 
have speed= specified, it reads the data from my disks.

- -- 
Greg Madden
Debian GNU/Linux
-BEGIN PGP SIGNATURE-
Version: GnuPG v1.2.2 (GNU/Linux)

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H+Fi/vUSDMAvYfhCXSIVdHM=
=4nbU
-END PGP SIGNATURE-




Re: Accessibility of official jigdo files for Sarge

2003-08-01 Thread Richard Atterer
On Thu, Jul 31, 2003 at 09:26:52PM +0200, Richard Atterer wrote:
> Hm, is this feature also somehow available in the Debian zlib packages? 
> jigdo-file uses zlib to compress the .template files...

Hm, it just occurred to me that it might be possible for me to allow
rsyncability for .template files even without a patched zlib!

The gzip patch works by calculating a rolling checksum for the last n bytes
of the _un_compressed data. Whenever the checksum reaches a magic value
(0), the compress stream is flushed. This ensures that the flushing always
takes place at the same positions, just after the same data patterns.

With my knowledge about the .template files, I can do a similar (possibly
even better) thing: The compressed part of the .template consists of chunks
of image data which were not matched by any .deb in the Debian mirror.
Flushing between writing those chunks will do the trick.

To prevent this from affecting the compression ratio too much, it mustn't
happen too often, but current versions of jigdo-file already flush the
stream from time to time for other reasons, so it should be possible to
just move the "boundary" of the flush in an rsync-friendly way.

Cheers,

  Richard

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  |_) /|  Richard Atterer |  GnuPG key:
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