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发信人: ccyker (cycker++), 信区: Linux
标 题: Debian Jigdo mini-HOWTO
发信站: 荔园晨风BBS站 (Fri Jan 10 21:06:08 2003), 转信
url: http://dirac.org/linux/debian/jigdo/debian-jigdo-mini-howto.html
Debian Jigdo mini-HOWTO
Peter Jay Salzman
p@dirac.org
Copyright ? 2001 by Peter Jay Salzman
2002-12-15 ver 0.116
Abstract
Getting Debian ISOs has always been a painful, slow and supremely
inefficient process. Jigdo is a new tool for obtaining Debian ISOs in an
easy, fast and very efficient manner. This HOWTO describes why you
should use jigdo, a little bit about how it works and how you use it
to get and update Debian ISOs.
Jigdo is a very general tool, and isn't tied specifically to Debian
ISOs. The jigdo tools can be used to make any ISO available for download
in the same easy, fast and efficient manner they're used for Debian
ISOs. This HOWTO will cover this as well, but we'll focus primarily on
downloading Debian ISOs.
------------------------------------------------------------------------
--------
Table of Contents
1. Administrata
1.1. Authorship and Copyright
1.2. Acknowledgements
1.3. Comments and Corrections
1.4. Latest Version And Translations
2. Why jigdo?
2.1. How Does One Get A Debian ISO Image Set?
2.2. Why Not Download The Whole ISO Image?
2.3. Why Not Use The Pseudo Image Kit (PIK)?
2.4. What Is Jigdo?
3. How Jigdo Works (optional)
3.1. Preparing The ISO For Download
3.2. The .template File
3.3. The .jigdo File
3.4. Downloading The Image
4. Downloading Your First Image (In 5 Easy Steps)
4.1. Install Jigdo
4.2. Download The .template And .jigdo Files
4.3. Run jigdo-lite
4.4. Specify A Mirror
4.5. Downloading Of The ISO
5. Updating Your Image
6. Frequently Asked Questions
6.1. [11 Aug 2002]: Can I have two jigdo-lite sessions at the same
time in the same directory?
6.2. [11 Aug 2002]: Why aren't the translations of this HOWTO on LDP?
6.3. jigdo takes a bit long to download the files because wget keeps
disconnecting and then reconnecting to the FTP server for each file.
Is there a way to make it faster?
6.4. How can I make jigdo use a proxy?
6.5. What do I do if my jigdo download gets interrupted?
6.6. My jigdo download won't complete because the .jigdo file is broken.
When I download a new, fixed .jigdo file, do I need to download all the
data over again?
6.7. Can I use jigdo to download images for DVD?
6.8. Can I burn the .iso.tmp file to CD?
6.9. Why doesn't jigdo work? It downloads some packages and deletes
them. I know it doesn't write them to the iso.tmp file because the
file size doesn't change!
6.10. I'm having trouble getting jigdo-easy to work.
6.11. I'm having trouble getting jigdo to download Sarge or Sid.
6.12. Jigdo-lite is too verbose. How can I supress some or all of its
messages?
6.13. Can I use jigdo on platforms other than Linux?
7. Errata
7.1. jigdo-easy
7.2. GUI Interface
7.3. jigdo-file-cache.db
7.4. Resources
1. Administrata
1.1. Authorship and Copyright
This document is copyright (c) 2001 Peter Jay Salzman, <p@dirac.org>.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1,
except for the provisions I list in the next paragraph. I hate HOWTO's
that include the license; it's a tree killer. You can read the GNU FDL
at http://www.gnu.org/copyleft/fdl.html.
If you want to create a derivative work or publish this HOWTO for
commercial purposes, contact me first. This will give me a chance to
give you the most recent version. I'd also appreciate either a copy of
whatever it is you're doing or a spinach, garlic, mushroom, feta
cheese and artichoke heart pizza.
------------------------------------------------------------------------
--------
1.2. Acknowledgements
Originally, I was going to thank the author of jigdo, Richard Atterer,
simply for writing jigdo. Anyone who has obtained Debian ISOs by other
means will know why. However, my thanks needs to go further. This
HOWTO started out as some webpages I wrote about my experience with
jigdo. Richard took the time to email me extensive corrections,
clarifications and answers to questions I had about jigdo. Since then,
he has read my work many times. Richard is a developer who not only
cares about his work, but also about the people who use it. Sadly,
this is becoming less common in this busy world we live in. Thanks,
Richard!
I'd also like to thank Conrad Wood, Elcio Mello and Marcelo Ramos for
translating this mini-HOWTO. I feel totally honored that they have found
my words worthy of their time and effort. Thanks, guys!
------------------------------------------------------------------------
--------
1.3. Comments and Corrections
I care a great deal about the people who use this document. Even
mini-HOWTOs take a long time to write, and I wouldn't have invested so
much effort into something people don't understand. If you have
comments, corrections or suggestions, even in matters like writing
style, don't hesitate to email me. As long as I'm not totally swamped by
my PhD, I'll do my best to respond to each email I receive about this
mini-HOWTO.
------------------------------------------------------------------------
--------
1.4. Latest Version And Translations
Conrad Wood <cnw@conradwood.net> has translated this HOWTO to German.
Elcio Mello <mello@ajato.com.br> has translated this HOWTO to
Portuguese.
Marcelo Ramos <mramos@montevideo.com.uy> has translated this HOWTO to
Spanish.
The translations are available from http://www.dirac.
org/linux/debian/jigdo. See Section 6.2.
The stable English version can be found at The Linux Documentation
Project: http://tldp.org/docs.html in the mini-HOWTO section. If you
want to see the work in progress, you can get the "bleeding edge"
version from http://www.dirac.org/linux/debian. If you'd like to
translate this mini-HOWTO to another language, please contact me at
<p@dirac.org>.
------------------------------------------------------------------------
--------
2. Why jigdo?
2.1. How Does One Get A Debian ISO Image Set?
If you want your own set of Debian CDs there are many ways of getting
them. One way is to buy them from vendors who sell Debian CDs. This
has some merit since some of the vendors donate money back to the Debian
project. Your donations help make sure that Debian is around for a long
time.
Another way of getting a set of Debian CDs is to burn your own set. This
first entails obtaining an ISO image and then burning that ISO image to
a blank CD. Before jigdo, there were two ways of creating Debian CDs:
Downloading the entire ISO
Using the pseudo-image kit (PIK)
This document is about the new and better way of obtaining Debian ISO
images, using a tool called jigdo. In fact, the PIK is now deprecated.
The canonical method of getting Debian ISO images is with jigdo.
------------------------------------------------------------------------
--------
2.2. Why Not Download The Whole ISO Image?
There are mirrors which offer http and ftp downloads of Debian ISOs. The
problem is that there are very few mirror sites, and their bandwidth
can't support everyone who wants Debian ISOs. For example, fsn.hu has
reportedly saturated the connection of its provider. The outgoing
traffic reaches a few terabytes per month!
In addition, Debian testing and unstable get updated often. Your ISOs
may become outdated the same day you download them unless you find
some sneaky way of updating them like mounting the ISO on a loopback
device and using rsync (which is what the PIK does). So if you want
up-to-date ISO images, you must download a new set of ISO images every
day. Clearly, this is not the way you want to obtain Debian ISOs!
Even if you want to download the stable ISO images, they still get
updated every few months. Downloading the ISO images will give you
up-to-date images for a few months, but every time a new revision of
Debian stable is released, you'll need to go through the painful process
of downloading the entire ISO set from scratch. This is not a good
use of your time and the mirror's resources.
------------------------------------------------------------------------
--------
2.3. Why Not Use The Pseudo Image Kit (PIK)?
The PIK addresses most of the problems of downloading entire ISO images.
The downloads are fast, and the PIK uses rsync to update only those
portions of an ISO image that need to be updated, so it's an efficient
way of keeping your ISO set up-to-date. However, there are some hefty
problems with the PIK:
It's difficult to use and not very user friendly.
You can't use the PIK to download testing and unstable ISO sets.
The PIK relies on rsync which is CPU-intensive for the server. If too
many people use PIK with the same server, it would go up in smoke.
Even if the PIK is made more friendly for the user, it's unacceptably
unfriendly for the mirrors.
The PIK uses rsync, which is blocked by many of the stricter firewalls.
So even if you wanted to use that nice fast corporate network at work,
you might run into problems using the PIK.
Each image needs to be stored on the server. That was OK in the good old
Potato days, when the 28 CD images "only" took 17 GB. Starting with
Woody, the 96 CDs need 57 GB or so. Now imagine that we also want to
offer DVDs and this figure doubles.
------------------------------------------------------------------------
--------
2.4. What Is Jigdo?
Jigdo (which stands for "Jigsaw Download") was written by Richard
Atterer and is released under the GNU GPL. It's a tool that allows
efficient downloading and updating of an ISO image. Any ISO image. Jigdo
is not Debian specific, however Debian has chosen it to be the prefered
method of downloading ISO images.
The jigdo tool comes with two utilities:
jigdo-file is used by the person offering the ISO image. It enables
anyone to download that image by creating a .jigdo and .template file
for the image.
jigdo-lite is used by people who want to download the ISO image. It
downloads the image using the image's .jigdo and .template files which
were created by jigdo-file. If your main concern is simply downloading
Debian ISO images, you'll just be using jigdo-lite.
A common misconception is that jigdo creates ISO images; it doesn't.
Jigdo-file simply allows people to download an ISO image by creating a
.jigdo and .template file. The people who want to download the ISO image
will get these two files and use jigdo-lite to download the image.
The ISO image needs to be made in advance, before jigdo-file is used,
and that's usually done with a utility like mkisofs or debian-cd.
Jigdo addresses all the problems with the other two methods of obtaining
Debian ISO images:
It's much faster than downloading the entire ISO image.
Unlike downloading the entire ISO image, it can take an outdated CD
(or a loop mounted outdated ISO image), download only the files that
have changed since the CD (or ISO image) was created and create a new
updated ISO. Very similar to how you use cvs to update source code.
jigdo-lite is much easier to use than the PIK.
jigdo-lite uses wget which, by default, uses http to transfer files. The
PIK uses rsync. While rsync may be blocked by some firewalls, the
only firewalls that block http are the ones from which you shouldn't
be using jigdo to begin with. You'll almost never run into firewall
problems with jigdo-lite.
jigdo-lite is much more user friendly than the PIK.
jigdo-lite is much more server friendly than the PIK.
Clearly, jigdo is the best method of obtaining Debian ISO images.
------------------------------------------------------------------------
--------
3. How Jigdo Works (optional)
You don't need to know this material to use jigdo, but it may help
demystify what jigdo does. If you're not interested in the details,
simply fast forward to Section 4, "How Do I Use Jigdo".
There are two components to jigdo:
jigdo-file: Prepares an ISO for download (used by the person offering
the ISO)
jigdo-lite: Downloads the ISO (used by the person downloading the ISO)
------------------------------------------------------------------------
--------
3.1. Preparing The ISO For Download
A CD image is a filesystem called iso9660, but for this discussion, we
can safely talk about a CD image as being a big file called an "ISO
image" (about 650MB) that contains files at various offsets. For
instance, if a CD contains a 567 byte file named README, the ISO image
might contain the README file's contents between offsets 20480000 and
20480567. You can visualize a CD image as:
--------------------------------------------------------
ISO Image: |xxxx| file-0 |xx| file-1 |xxx| file-2 |x| file-3
|xxxx|
--------------------------------------------------------
The "x" areas of the image contain things like directory information,
zero padding, disk name, boot block, etc.
jigdo-file takes two things as input: the complete CD image (so the
ISO already needs to have been made) and a set of files which may or may
not be in the image. Here's a visualization of jigdo-file's input:
--------------------------------------------------------
ISO Image: |xxxx| file-0 |xx| file-1 |xxx| file-2 |x| file-3
|xxxx|
--------------------------------------------------------
---------- ---------- ----------
----------
Loose Files: | file-0 | | file-1 | | file-3 |
| file-4 |
---------- ---------- ----------
----------
Through magic, jigdo-file finds out which of the loose files are
contained in the ISO image and their offsets within the ISO file. It
outputs two files: a ".template" file and a ".jigdo" file.
------------------------------------------------------------------------
--------
3.2. The .template File
Given an input of an ISO image and a set of files which may or may not
be in the ISO image, jigdo-file outputs a .template file for that ISO
image. Here's what the .template file looks like:
--------------------------------------------------------
.template: |xxxx| md5-0 |xx| md5-1 |xxx|cccccccc|x| md5-3
|xxxx|
--------------------------------------------------------
jigdo-file found that the files file-0, file-1 and file-3 were contained
in the ISO image. It removed the contents of the these files and
replaced them with each file's md5 checksum (the md5-0, md5-1, etc).
The "x" data (directory information, zero padding, etc) within the ISO
image is compressed and written to the .template file. Finally, any
files within the ISO image that weren't supplied as loose files (like
file-2) are also compressed and written to the .template file. This is
shown as "c" data in the .template file visualization.
Loose files which were supplied to jigdo-file that aren't found in the
ISO image (like file-4) are ignored.
------------------------------------------------------------------------
--------
3.3. The .jigdo File
Given an input of an ISO image and a set of loose files which may or may
not be in the ISO image, jigdo-file outputs a .jigdo file for that
ISO image. The Debian .jigdo files are gzipped, so you need to use
zcat or zless to view them. Here's what a .jigdo file looks like when
you gunzip it:
md5-0=http://somemirror.org/file-0
md5-1=http://somemirror.org/file-1
md5-2=http://somemirror.org/file-2
md5-3=http://somemirror.org/file-3
The .jigdo file simply provides a mapping between the md5sum of a file
within the ISO image and the download URL of that file. There are some
other things within the .jigdo file, and if you look through it,
you'll see the .jigdo file has the same format as a ".ini" file. It
should be self explanatory, but if you want the nitty-gritty details,
see the jigdo documentation.
The format shown above is not quite what you'd see in a typical .jigdo
file, but it's very similar. If you look at the [Servers] section at the
bottom of the .jigdo file, you'll see exactly what the difference is
between what I showed above and an actual .jigdo file.
------------------------------------------------------------------------
--------
3.4. Downloading The Image
Once you use jigdo-file to generate a .jigdo and .template file for an
ISO image, anyone can use jigdo-lite to download that image.
jigdo-lite downloads all the files of a Debian ISO using wget, assembles
them and forms a copy of the original ISO image on the fly.
------------------------------------------------------------------------
--------
4. Downloading Your First Image (In 5 Easy Steps)
We'll assume that you're starting from scratch and don't have any Debian
ISOs on hand. Once you burn your set of ISOs, you can use jigdo-lite
later to update them. We'll cover updating your ISOs in the next
section.
------------------------------------------------------------------------
--------
4.1. Install Jigdo
First install the jigdo-file package:
# apt-get install jigdo-file
Jigdo is under aggressive development. Bug fixes and improvements are
constant, so if you're using stable or testing, download jigdo-file from
unstable at http://packages.debian.org/unstable/utils/jigdo-file.html.
As of 19 July 2002 it's at version 0.6.8. This is the version used
for the examples of this HOWTO.
Note to Woody users: The version of jigdo-lite which comes with Woody
(rev 0) is not capable of downloading Sarge or Sid. See Section 6.11.
------------------------------------------------------------------------
--------
4.2. Download The .template And .jigdo Files
For each ISO image you want to download, you'll need two files:
The .jigdo file for the disk image you want to download.
The .template file for the disk image you want to download.
Example: Woody has 8 images, so you need to download 8 .jigdo files
and 8 .template files. They can be downloaded from http://www.debian.
org/CD/jigdo-cd/ and are named woody-i386-1.iso.jigdo, woody-i386-1.
iso.template, ..., and woody-i386-8.iso.template.
Alternatively, instead of downloading a .jigdo and .template file for
each ISO image, you can give jigdo-lite an URL that points to the .jigdo
file that you need, like http://a.mirror/woody-i386-1.jigdo. jigdo-lite
will download the relevent .jigdo and .template files on the fly.
However, if you're a bit nervous about using jigdo-lite for the first
time, just download the files and I'll walk you through the process.
------------------------------------------------------------------------
--------
4.3. Run jigdo-lite
Run jigdo-lite and give it the .jigdo file of the image you want to
download. Using Woody as an example:
$ jigdo-lite woody-i386-1.jigdo
Alternatively, if you're working with an URL to the .jigdo file rather
than a copy of the .jigdo file on your hard drive, run jigdo-lite with
an argument of the URL:
$ jigdo-lite http://a.mirror/woody-i386-1.jigdo
You'll see something like:
-----------------------------------------------------------------
Jigsaw Download "lite"
Copyright 2001-2002 by Richard Atterer <jigdo@atterer.net>
Getting mirror information from /etc/apt/sources.list
-----------------------------------------------------------------
Images offered by `woody-i386-1.iso.jigdo':
1: woody-i386-1.iso
-----------------------------------------------------------------
If you already have a previous version of the CD you are
downloading, jigdo can re-use files on the old CD that are also
present on the new image, and you do not need to download them
again. Mount the old CD ROM and enter the path it is mounted
under
(e.g. `/mnt/cdrom'). Alternatively, just press enter if you want
to start the download of any remaining files.
Files to scan:
If you forget to pass jigdo-lite a .jigdo file, it will prompt you for
one (or an URL that points to one).
If you suspended jigdo-lite with cntrl-z (don't do this; I'll tell you
what you'd see) and did an ls, you'd find a new file in the directory
named woody-i386-1.iso.jigdo.unpacked. This file is simply a gunzip'ed
version of the .jigdo file.
Right now, jigdo-lite is telling us that if we did have an outdated
version of the CD, to give the pathname to the CD. Since we're
assuming that you're starting from scratch and have no Debian ISOs yet,
we have nothing to scan (we'll cover this in Section 5). So just
press <ENTER>.
------------------------------------------------------------------------
--------
4.4. Specify A Mirror
You'll see:
-----------------------------------------------------------------
The jigdo file refers to files stored on Debian mirrors. Please
choose a Debian mirror as follows: Either enter a complete URL
pointing to a mirror (in the form
`ftp://ftp.debian.org/debian/'), or enter any regular expression
for searching through the list of mirrors (try a two-letter
country code such as `de', or a country name like `United
States', or a server name like `sunsite'):
Debian mirror [http://linux.csua.berkeley.edu/debian//]:
jigdo-lite is smart enough to use the mirror that you use for your
Debian updates by pulling it from /etc/apt/sources.list (you can see
that I use linux.csua.berkeley.edu for my updates). If you wanted to use
a different mirror, you would specify a different mirror here. If
this is the mirror you want to use, press <ENTER>. Jigdo-lite will
then write a .jigdo-lite file in your home directory.
Next, if the .jigdo file you're using references a package which needs
to be downloaded from a Non-US server (software encumbered by US
export restrictions), jigdo-lite will prompt you for a Non-US server.
The message displayed (and your response) will be very similar to the
mirror dialog described in the previous paragraph. The only difference
is that you need to specify (or accept the default value for) a Non-US
server. If the ISO image you're about to download contains Non-US
software, you'll see:
-----------------------------------------------------------------
The jigdo file also refers to the Non-US section of the Debian
archive. Please repeat the mirror selection for Non-US. Do not
simply copy the URL you entered above; this does not work
because
the path on the servers differs!
Debian non-US mirror [http://linux.csua.berkeley.
edu/debian-non-US//]:
and jigdo-lite will write your choice to your $HOME/.jigdo-lite file.
However, if the image you're about to download doesn't contain Non-US
software you won't see this dialog.
Note that you can reset the default mirrors that jigdo uses for your
future downloads in $HOME/.jigdo-lite file with the following lines:
debianMirror='http://some-mirror-to-use/debian/'
nonusMirror='http://some-other-mirror/debian-non-US/'
------------------------------------------------------------------------
--------
4.5. Downloading Of The ISO
After specifying the mirror(s), jigdo-lite will look for the .template
file. If it can't find one, it'll download a .template file from a
mirror. After it finds the .template file (or after it downloads one),
you'll see:
-----------------------------------------------------------------
Merging parts from `file:' URIs, if any...
Found 0 of the 1224 files required by the template
Will not create image or temporary file - try again with different
input files
--13:38:08-- http://linux.csua.berkeley.
edu/debian/pool/main/b/bind9/
lwresd_9.2.1-2.woody.1_i386.deb => `lwresd_9.2.1-2.woody.
1_i386.deb'
Resolving linux.csua.berkeley.edu... done.
Connecting to linux.csua.berkeley.edu[128.32.247.238]:80...
connected.
HTTP request sent, awaiting response... 200 OK
Length: 157,318 [application/x-debian-package]
30% [==========> ] 47,418 113.22K/s
ETA 00:00
...
After the .template file was found (or after it was downloaded),
jigdo-lite begins pulling packages onto your hard drive. There will be
alot of messages flying across your screen. If this is confusing to you,
see Section 6.12. While jigdo-lite is downloading the packages,
switch to another console (or open another xterm) and do an ls in the
directory you're running jigdo-lite in. Now there should be 6 files in
the directory:
debian-30r0-i386-binary-1.iso.list
debian-30r0-i386-binary-1.iso.tmp
jigdo-file-cache.db
tmp/
woody-i386-1.jigdo
woody-i386-1.jigdo.unpacked
woody-i386-1.template
woody-i386-1.iso.tmp won't appear right away. It's a temporary version
of the ISO file that gets written to every so often.
jigdo-file-cache.db is a Berekeley DB file containing md5sums of any
files read in when you specify a directory at the Files to scan: prompt.
It's more fully described in Section 7.3.
tmp/ is a directory containing Debian package files that get downloaded.
For instance, as I write this, it contains:
$ ls tmp/
alsa-headers-0.5_0.5.12a-2_all.deb tkdiff_3.08-3_all.deb
alsa-utils-0.4_0.4.1-9.1_i386.deb xfonts-intl-chinese-big_1.
2-2.1_all.deb
gnuserv_3.12.4-3_i386.deb xmanpages-ja_4.1.0.
20011224-1_all.deb
pilot-link_0.9.5.0-8_i386.deb xscreensaver_3.34-3_i386.deb
smpeg-plaympeg_0.4.4-8_i386.deb
Every so often, the directory gets flushed and the files get added to
woody-i386-1.iso.tmp.
At this point, go play some Quake III because this will take some time
(you may want to play on a different machine because jigdo is very
disk intensive when it assembles the ISO file). At some point, the
download will finish and you'll be staring at:
FINISHED --13:32:58--
Downloaded: 7,469,872 bytes in 9 files
Found 9 of the 9 files required by the template
Successfully created `woody-i386-3.raw'
-----------------------------------------------------------------
Finished!
The fact that you got this far is a strong indication that
`woody-i386-3.raw'
was generated correctly. I will perform an additional, final
check,
which you can interrupt safely with Ctrl-C if you do not want to
wait.
OK: Checksums match, image is good!
$
------------------------------------------------------------------------
--------
5. Updating Your Image
Presumably, you've read the last section, followed the instructions,
burned your newly created ISO files onto CD and are feeling warm and
fuzzy. Sooner or later, some packages will get updated and now you
want to donate your old CDs to some newbie at your local LUG's
installfest and burn yourself a set of updated CDs. Since you're well on
the way to becoming a jigdo-guru, we won't go into as much painful
detail as we did in the last section.
The first step is to download the .jigdo and .template files, again, for
the images you want to update. You may wonder why you need to
download them a second time. The reason is because the updated image you
want to download has changed. Files may have been added or deleted, but
even if not, any updated packages or files will have a different
checksum from the checksum listed in the .jigdo and .template files
you used when you first downloaded the images.
At this point, you're either holding an outdated Debian CD in your
hand or you have the CD's outdated ISO image on your hard drive. Let's
go through the steps of getting an updated ISO file. If you have a CD,
put it in your CD drive and mount it:
$ mount /cdrom
On the other hand, if you have an ISO file you'd like to update, mount
it as a loop device (you may need to be root to do this). I'll be
updating my Woody image, since I noticed that Woody just got a few
security updates:
# mount -o loop woody-i386-1.iso /mnt
Now run jigdo-lite with the .jigdo file as an argument.
$ jigdo-lite woody-i386-1.jigdo
-----------------------------------------------------------------
Jigsaw Download "lite"
Copyright 2001-2002 by Richard Atterer <jigdo@atterer.net>
Loading settings from `/home/p/.jigdo-lite'
-----------------------------------------------------------------
Images offered by `woody-i386-1.jigdo':
1: Debian GNU/Linux 3.0 r0 Woody - Official i386 Binary-1 CD
(debian-30r0-i386-binary-1.iso)
Further information about `debian-30r0-i386-binary-1.iso':
Generated on Thu, 18 Jul 2002 14:34:12 +0100
-----------------------------------------------------------------
If you already have a previous version of the CD you are
downloading, jigdo can re-use files on the old CD that are also
present on the new image, and you do not need to download them
again. You found the secret message; you're a very careful
reader. Mount the old CD ROM and enter the path it is mounted
under (e.g. `/mnt/cdrom'). Alternatively, just press enter if
you
want to start the download of any remaining files.
You can also enter a single digit from the list below to
select the respective entry for scanning:
1: /mnt
Files to scan:
jigdo-lite is asking us to give it the location of your mounted CD (if
you're updating a CD) or your loop mounted ISO file (if you're using the
ISO file). I'm using an ISO file loop mounted on /mnt, so I'll enter
/mnt. If you're updating a CD, enter the mount directory of your CD,
which is most likely /cdrom. In either case, jigdo-lite will scan the
directory of your mounted media, determine which files need updating and
re-use the files which don't need updating. You may see something
like:
Files to scan: /mnt/other
Not downloading .template file - `woody-i386-1.template' already
present
jigdo-file: Output file `debian-30r0-i386-binary-1.iso' already
exists - delete
it or use --force
jigdo-file failed with code 3 - aborting.
What happened? Actually, I wanted to show you this because you'll bump
into it sooner or later. I'm updating an ISO file, but the outdated
image file is in the same directory I'm working in. Jigdo-lite wants
to generate a file called woody-i386-1.iso but there's already a file by
that name in the current directory (the outdated image). Jigdo-lite
doesn't want to destroy that file, so it bails and lets me know that I
can either delete that file or use --force to overwrite the file. You
could also rename or move the file too, but I guess jigdo-lite assumes
we already know this. :-)
Don't be timid about moving or renaming the image file just because it's
loop mounted. The filesystem uses inodes under the hood, and even if
you move or rename the file, the inode stays the same. You won't hurt
the filesystem mounted under /mnt. As for deleting the ISO file, that
won't hurt the mounted filesystem either. A file's inode gets
deallocated only when the inode's reference count drops to zero.
Mounting the ISO image bumps the reference count up, so the file
really gets deleted only after you rm the file and umount the loop
device. All you people who are updating the CD don't have to worry about
any of this. :-)
I'll rename the ISO file to woody-i386-1.iso.old and run jigdo-lite
again. Let's try again:
$ jigdo-lite woody-i386-1.jigdo
-----------------------------------------------------------------
Jigsaw Download "lite"
Copyright 2001-2002 by Richard Atterer <jigdo@atterer.net>
Loading settings from `/home/p/.jigdo-lite'
-----------------------------------------------------------------
Images offered by `woody-i386-1.jigdo':
1: Debian GNU/Linux 3.0 r0 Woody - Official i386 Binary-1 CD
(debian-30r0-i386-binary-1.iso)
Further information about `debian-30r0-i386-binary-1.iso':
Generated on Thu, 18 Jul 2002 14:34:12 +0100
-----------------------------------------------------------------
If you already have a previous version of the image you are
downloading, jigdo can re-use files on the old image that are
also
present on the new image, and you do not need to download them
again. Mount the old CD ROM and enter the path it is mounted
under
(e.g. `/mnt/cdrom'). Alternatively, just press enter if you want
to start the download of any remaining files.
You can also enter a single digit from the list below to
select the respective entry for scanning:
1: /mnt
Files to scan: /mnt
Not downloading .template file - `woody-i386-1.template' already
present
...
Found 1200 of the 1224 files required by the template
...
jigdo-lite remembers that I wanted to scan /mnt and tells me I can
either type 1 to scan that directory or type the directory in again.
Since I'm a perverse person, I type the name of the directory again.
The ellipsis represent some text that changes rapidly. The first
ellipsis is a dynamic list of what files jigdo-lite is scanning. The
second ellipses deonotes progress in writing woody-i386-1.iso.tmp.
Once jigdo-lite finishes scanning the files and writing the temporary
ISO file, it prints:
Copied input files to temporary file `woody-i386-1.iso.tmp'
- repeat command and supply more files to continue
-----------------------------------------------------------------
If you already have a previous version of the image you are
downloading, jigdo can re-use files on the old image that are
also
present on the new image, and you do not need to download them
again. Mount the old CD ROM and enter the path it is mounted
under
(e.g. `/mnt/cdrom'). Alternatively, just press enter if you want
to start the download of any remaining files.
You can also enter a single digit from the list below to
select the respective entry for scanning:
1: /mnt
Files to scan:
Since you normally don't have another source of files to scan other than
your loop mounted ISO file (or your CD), press <ENTER>. Jigdo-lite will
then ask you about which mirrors you want to use, just like it did when
you downloaded your ISO for the first time. You've already answered
these questions before, but if you truly don't remember, you might
want to re-read Section 4.4.
At this point, you'll see jigdo-lite working its magic. Now wasn't
that easy?
------------------------------------------------------------------------
--------
6. Frequently Asked Questions
Questions prepended with a date indicate a time sensitive question, in
other words, a question that relates to a temporary situation. If you
see one of these questions and know that the temporary situation has
changed, please contact me and let me know so I can remove the
question from the mini-HOWTO.
------------------------------------------------------------------------
--------
6.1. [11 Aug 2002]: Can I have two jigdo-lite sessions at the same
time in the same directory?
Not at the moment. The two sessions will clash over the tmp/ and
jigdo-file-cache.db files. This will being worked on. If you want to run
concurrent jigdo-lite sessions, use different working directories.
------------------------------------------------------------------------
--------
6.2. [11 Aug 2002]: Why aren't the translations of this HOWTO on LDP?
I've been having trouble getting the translations of this HOWTO
submitted to the non-English LDP editors.
The German LDP editor, Marco Budde <Budde@tu-harburg.de> refuses to
accept the German translation because it was written in Docbook and
not Linuxdoc, even though Docbook is the preferred SGML language for the
LDP.
The Portuguese LDP editor, Alfredo Carvalho <ajpc@poli.org>, has
completely ignored my submission of the Portuguese translation.
If you care about having LDP documents in these languages, I urge you to
write to these editors and ask them to please be more responsible about
accepting translated documents. For the time being, you can download
these translations from my personal website, http://www.dirac.
org/linux/debian/jigdo.
------------------------------------------------------------------------
--------
6.3. jigdo takes a bit long to download the files because wget keeps
disconnecting and then reconnecting to the FTP server for each file.
Is there a way to make it faster?
The download speed can be increased by using an HTTP instead of an FTP
server - FTP is not a very efficient protocol for downloading lots of
small files. Additionally, you may want to upgrade to the latest version
of wget, because that version supports persistent HTTP connections,
which results in another slight speed increase.
Unfortunately, even with persistent HTTP connections, the download speed
will not be as high as that of a single-file ISO download. Such
speeds can only be achieved with HTTP pipelining - the jigdo GUI
application will support pipelining.
------------------------------------------------------------------------
--------
6.4. How can I make jigdo use a proxy?
This is described on http://debian.org/CD/jigdo-cd/ as well as the
README of the jigdo-lite tarball.
------------------------------------------------------------------------
--------
6.5. What do I do if my jigdo download gets interrupted?
If your download gets interrupted, all you need to do is restart
jigdo-lite and hit <ENTER> at all the question prompts. Jigdo-lite
will pick up where it left off.
------------------------------------------------------------------------
--------
6.6. My jigdo download won't complete because the .jigdo file is broken.
When I download a new, fixed .jigdo file, do I need to download all the
data over again?
You may find that the .jigdo file you downloaded is broken. It's very
uncommon, but it does happen from time to time with moving targets
like Debian testing or unstable.
If you find that your .jigdo file is broken, you'll need to download a
new .jigdo file (when a fixed one becomes available), but you won't need
to download all the ISO data again.
You can use the same loop mounting trick we use when updating an ISO
image. The difference is that there's no finished .iso file to start
with, but the .iso.tmp file is an ISO image too and can be used to
finish the download without having to re-download all the data that
was downloaded before the broken .jigdo file caused jigdo-file to halt.
Simply loop mount the .iso.tmp file on /mnt and when you re-run
jigdo-lite with the fixed .jigdo file, tell jigdo-lite to scan /mnt.
Don't forget to rename or move the .iso.tmp file so it doesn't interfere
with jigdo-lite which will want to create a new .iso.tmp file.
------------------------------------------------------------------------
--------
6.7. Can I use jigdo to download images for DVD?
Absolutely; the process is identical to downloading CD images. The
only thing you need to do differently is to download the .jigdo and .
template files for DVDs instead of CDs. You can find the DVD .jigdo
and .template files at http://www.debian.org/CD/jigdo-cd/.
Note that you need Linux 2.4 or later to create DVD-sized files. Under
Windows, DVD-sized images can't be created at all at the moment
because the C++ library of the mingw gcc port doesn't have big file
support yet.
------------------------------------------------------------------------
--------
6.8. Can I burn the .iso.tmp file to CD?
We haven't tried yet, but it should be possible. You'd probably find
some files are filled with "0"'s. If someone tries it, please contact me
at <p@dirac.org> and let me know what happened.
But more importantly, why would you WANT to do this? :-)
------------------------------------------------------------------------
--------
6.9. Why doesn't jigdo work? It downloads some packages and deletes
them. I know it doesn't write them to the iso.tmp file because the
file size doesn't change!
Jigdo works just fine - the .iso.tmp file is created at the beginning
with its final size, but filled with zero bytes. Later, parts of it
are overwritten with the downloaded data.
You can tell that jigdo is making progress by looking at the messages
"Found X of the Y files required by the template" that are printed
from time to time. The second value "Y" should decrease. When it reaches
zero, the download is finished.
------------------------------------------------------------------------
--------
6.10. I'm having trouble getting jigdo-easy to work.
See Section 7.1.
------------------------------------------------------------------------
--------
6.11. I'm having trouble getting jigdo to download Sarge or Sid.
If you're using Potato or Woody, upgrade to jigdo-lite 0.6.8. Because of
a change in Jigdo, the version of jigdo-lite that comes with Woody (rev
0) cannot download Sarge and Sid images. The version that comes with
Sarge is sufficient (Section 7.4).
If you're using Sarge or Sid, then you may need some help. Search the
archives of the debian-cd mailing list, and if that doesn't solve your
problem, you should send them a request for help (Section 7.4).
------------------------------------------------------------------------
--------
6.12. Jigdo-lite is too verbose. How can I supress some or all of its
messages?
Jigdo-lite uses wget, and wget's output can be quite verbose. If this is
unsettling, you can make wget more quiet by adding --non-verbose to the
wgetOpts switch in your ~/.jigdo-lite file. If you want wget to print
no messages at all, use --quiet in the wgetOpts switch.
------------------------------------------------------------------------
--------
6.13. Can I use jigdo on platforms other than Linux?
Certainly. If you're interested in Potato or Woody under Microsoft
Windows, old SunOS, HP-UX and IRIX you can use jigdo-easy. See Section
7.1 and Section 7.4.
If you want to download Potato, Woody, Sarge or Sid under Microsoft
Windows, jigdo-lite has been ported to that platform and can be
downloaded from the main jigdo site (Section 7.4).
------------------------------------------------------------------------
--------
7. Errata
7.1. jigdo-easy
Jigdo-easy, by Anne Bezemer, is a fork from jigdo-lite which is portable
to a wider range of systems, including Microsoft Windows, old SunOS,
HP-UX and IRIX). It's also easier to use than jigdo-lite but because
of changes made to Jigdo, will only work with Potato and Woody.
Jigdo-easy will not be able to download Sarge and Sid. See Section 7.4
and Section 6.13.
------------------------------------------------------------------------
--------
7.2. GUI Interface
A GTK+ interface to jigdo is currently being worked on. It's not fully
functional yet, but will be available at some point. There will be a
Linux as well as a Windows GUI client.
------------------------------------------------------------------------
--------
7.3. jigdo-file-cache.db
The cache contains the md5sums of files read when you supply a directory
at the Files to scan: prompt. If you have jigdo-file scan the same
directory a second time, the scan will be very fast.
This could be useful in the following case: rev0 gets updated to rev1.
With the rev1 CD images, some packages may have been pushed from CD n to
CD n+1, or vice versa. If you had a particularly slow link (e.g.
modem), you'd try to avoid downloading these packages again. For this
reason, when downloading the new version of CD n, you'd let jigdo-lite
scan the three CDs n-1, n and n+1 (or even all 8 CDs if you want to be
100% sure).
If you have jigdo-lite scan the same CDs over and over again while
updating each of the 8 CD images, the cache will prevent all the data on
the CDs from being read multiple times.
The cache is much more important when generating jigdo files, because
you don't want jigdo-file to read in your whole 50GB Debian mirror for
every generated jigdo file.
------------------------------------------------------------------------
--------
7.4. Resources
This HOWTO is winding down to a close, but I thought I'd leave you
with a few links and references to learn more about the jigdo tools
and how they work.
http://atterer.net/jigdo
This is the jigdo home site. You should definitely browse this site;
lots of information about ports, GUI clients and everything under the
sun relating to jigdo.
http://cdimage.debian.org/~costar/jigdo
The Debian page for jigdo-easy (Section 7.1).
http://www.debian.org/CD/jigdo-cd
The main Debian page for jigdo.
http://packages.debian.org/testing/utils/jigdo-file.html
If you're using Potato or Woody, please upgrade jigdo-file to version
0.6.8, which comes with Sarge (Section 6.11).
http://lists.debian.org/search.html
You can use this page to search the debian-cd mailing list archives.
http://www.debian.org/MailingLists/subscribe
The subscription page for the debian-cd mailing list.
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