[zt]Apt-Pinning for Beginners

completist

google上找到的，感觉不错，转来让兄弟们看看

http://jaqque.sbih.org/kplug/apt-pinning.html

1. 
   
2. Apt-Pinning for Beginners
   
3. Why apt-pinning?
   
4. 
   
5. Do you run Debian? Have you ever gotten annoyed at how Debian Stable always seems to be out of date?
   
6. 
   
7. I will show you a way that you can have apt mix-and-match between Stable, Testing, and Unstable sources. This will allow you to run a mostly-Stable system, but also track the latest and greatest of those packages that you are most keenly interested in.
   
8. 
   
9. Why do this? Stable is covered by the Security Team. Testing and Unstable are not. For non-critical services, like perhaps your mailer, or your window manager, this is not so important, and the newest versions may have additional features that are desired. It is these packages that are perfect for pinning to a version, other than Stable.
   
10. sources.list
    
11. 
    
12. The first step is to set up your /etc/apt/sources.list to include your typical Stable, plus the Testing/Unstable sources that you want.
    
13. 
    
14. A simple sources.list may look like this:
    
15. 
    
16. #Stable
    
17. deb http://ftp.us.debian.org/debian stable main non-free contrib
    
18. deb http://non-us.debian.org/debian-non-US stable/non-US main contrib non-free
    
19. 
    
20. #Testing
    
21. deb http://ftp.us.debian.org/debian testing main non-free contrib
    
22. deb http://non-us.debian.org/debian-non-US testing/non-US main contrib non-free
    
23. 
    
24. #Unstable
    
25. deb http://ftp.us.debian.org/debian unstable main non-free contrib
    
26. deb http://non-us.debian.org/debian-non-US unstable/non-US main contrib non-free
    
27. 
    
28. You would probably want to add your mirrors, security.debian.org, and perhaps the appropriate deb-src lines. Here is a copy of my actual sources.list.
    
29. preferences
    
30. 
    
31. The next step is to create/edit your /etc/apt/preferences file. preferences is where the apt-pinning takes place. Normally, the highest version of an available package wins, but we will override that.
    
32. 
    
33. A simple preferences file may look like this:
    
34. 
    
35. Package: *
    
36. Pin: release a=stable
    
37. Pin-Priority: 700
    
38. 
    
39. Package: *
    
40. Pin: release a=testing
    
41. Pin-Priority: 650
    
42. 
    
43. Package: *
    
44. Pin: release a=unstable
    
45. Pin-Priority: 600
    
46. 
    
47. Note the decending values. Since Stable has the highest pin-priority, it will be installed preferentially over Testing or Unstable.
    
48. 
    
49. My actual preferences file is what you see above.
    
50. apt-get update
    
51. 
    
52. Now we are ready to apt-get update. This will add the new repositories to apt's list.
    
53. E: Dynamic MMap ran out of room
    
54. 
    
55. You may find that you receive an error like the following:
    
56. 
    
57. E: Dynamic MMap ran out of room
    
58. E: Error occured while processing sqlrelay-sqlite (NewPackage)
    
59. E: Problem with MergeList /var/lib/apt/lists/ftp.us.debian.org_debian_dists_woody_contrib_binary-i386_Packages
    
60. E: The package lists or status file could not be parsed or opened.
    
61. 
    
62. This is caused because apt's cache is too small to handle all of the packages that are included with stable, testing, and unstable. This is also very easy to fix. Add the following line to /etc/apt/apt.conf
    
63. 
    
64. APT::Cache-Limit "8388608";
    
65. 
    
66. Thanks to R (Chandra) Chandras for pointing out this problem
    
67. Installing new packages
    
68. 
    
69. To install a new package, it is just as it ever was, apt-get install <package>. If the package exists in Stable, then that is what it will grab. If the package exists only in Unstable, then from Unstable it will be gotten.
    
70. 
    
71. What if the package exists in both Stable and Unstable, but we want the Unstable version? There are two ways we can do that, each with a slightly different syntax, and each with a slightly different effect.
    
72. 
    
73.     * apt-get install <package>/unstable
    
74. 
    
75.       This will install the unstable version of the package, and try to meet any dependencies from Stable. This may not work, but it will tell you why:
    
76. 
    
77. # apt-get install zsh/unstable
    
78. Reading Package Lists... Done
    
79. Building Dependency Tree... Done
    
80. Selected version 4.0.6-7 (Debian:unstable) for zsh
    
81. Some packages could not be installed. This may mean that you have
    
82. requested an impossible situation or if you are using the unstable
    
83. distribution that some required packages have not yet been created
    
84. or been moved out of Incoming.
    
85. 
    
86. Since you only requested a single operation it is extremely likely that
    
87. the package is simply not installable and a bug report against
    
88. that package should be filed.
    
89. The following information may help to resolve the situation:
    
90. 
    
91. Sorry, but the following packages have unmet dependencies:
    
92.   zsh: Depends: libc6 (>= 2.2.5-13) but 2.2.5-11.1 is to be installed
    
93. E: Sorry, broken packages
    
94. 
    
95.     * apt-get -t unstable install <package>
    
96. 
    
97.       This will install the Unstable version of the package, and try to meet any dependencies from Unstable. This may produce better results.
    
98. 
    
99. # apt-get -t unstable install zsh   
    
100. Reading Package Lists... Done
     
101. Building Dependency Tree... Done
     
102. The following extra packages will be installed:
     
103.   libc6 libc6-dev libc6-pic libdb1-compat locales
     
104. The following NEW packages will be installed:
     
105.   libdb1-compat
     
106. 5 packages upgraded, 1 newly installed, 0 to remove and 394  not upgraded.
     
107. Need to get 11.6MB of archives. After unpacking 606kB will be used.
     
108. Do you want to continue? [Y/n]
     
109. 
     
110. That's it!
     
111. 
     
112. Armed with a complete sources.list and a minimal preferences, you can go ahead and mix-and-match between the various Debian releases.
     
113. 
     
114. Have fun!
     
115. 
     

复制代码

也可看看 http://www.argon.org/~roderick/apt-pinning.html

1. 
   
2. Using APT with more than 2 sources
   
3. 
   
4. APT's Default-Release setting (aka apt-get --target-release) is useful if your /etc/apt/sources.list file contains exactly 2 releases (such as stable and testing, or testing and unstable). If you want to track more than 2 releases (stable, testing, and unstable, or two of those plus a non-Debian source), it has problems. This document explains how to do better. Updates can be found at http://www.argon.org/~roderick/apt-pinning.html.
   
5. Improved /etc/apt/preferences File
   
6. 
   
7. First, here are some reasonable /etc/apt/preferences files for the common cases. The rest of this document describes what these are doing.
   
8. 
   
9.     * Track stable:
   
10. 
    
11. Explanation: see http://www.argon.org/~roderick/apt-pinning.html
    
12. Package: *
    
13. Pin: release o=Debian,a=stable
    
14. Pin-Priority: 900
    
15. 
    
16. Package: *
    
17. Pin: release o=Debian,a=testing
    
18. Pin-Priority: 400
    
19. 
    
20. Package: *
    
21. Pin: release o=Debian,a=unstable
    
22. Pin-Priority: 300
    
23. 
    
24. Package: *
    
25. Pin: release o=Debian
    
26. Pin-Priority: -1
    
27. 
    
28.     * Track testing:
    
29. 
    
30. Explanation: see http://www.argon.org/~roderick/apt-pinning.html
    
31. Package: *
    
32. Pin: release o=Debian,a=testing
    
33. Pin-Priority: 900
    
34. 
    
35. Package: *
    
36. Pin: release o=Debian,a=unstable
    
37. Pin-Priority: 300
    
38. 
    
39. Package: *
    
40. Pin: release o=Debian
    
41. Pin-Priority: -1
    
42. 
    
43. "apt-get --default-release" Has No Memory
    
44. 
    
45. When you run "apt-get -t unstable install foo", this sets APT::Default-Release for this invocation of apt-get, but it doesn't affect future runs. This is useful in some circumstances, but problematic in others.
    
46. The Good
    
47. 
    
48. Say you've got testing and unstable in your sources.list, an APT::Default-Release of "testing" in apt.conf, no /etc/apt/preferences, and a package foo which is available from the releases like this:
    
49. 
    
50. release         version         priority
    
51. no -t switch         -t unstable
    
52. testing         1.1         990         500
    
53. unstable         1.2         500         990
    
54. 
    
55. If foo isn't installed and you run "apt-get install foo" you get version 1.1 from testing, since that version has the highest priority.
    
56. 
    
57. If you run "apt-get -t unstable install foo" instead you get version 1.2 from unstable, since the -t switch temporarily causes that version to have the highest priority.
    
58. 
    
59. foo will temporarily track unstable. If version 1.3 is uploaded to unstable while 1.1 is still in testing, we have:
    
60. 
    
61. release         version         priority
    
62. installed         1.2         100
    
63. testing         1.1         990
    
64. unstable         1.3         500
    
65. 
    
66. The highest priority version is 1.1, but this is lower than the installed 1.2. Since the priority of 1.1 is 990 (which is lower than 1000), apt-get will not downgrade to it. The next highest priority is 1.3 at 500. Since this is greater than the installed 1.2, it is selected.
    
67. 
    
68. foo will stop tracking unstable as soon as testing gets a version which is as new as the version which is currently installed. Say that version 1.3 migrates from unstable to testing, and then 1.4 is uploaded to unstable:
    
69. 
    
70. release         version         priority
    
71. installed         1.3         100
    
72. testing         1.3         990
    
73. unstable         1.4         500
    
74. 
    
75. Since the unstable 1.4 version now has a lower priority than the installed version, foo is not upgraded to it. Often this is what you want.
    
76. The Bad
    
77. 
    
78. APT::Default-Release's behavior works well when you're only tracking two different releases, but with 3 or more it starts to go wrong. When you install a package from 1 of the non-default releases, it can be immediately replaced with a newer version from another of them.
    
79. 
    
80. Consider:
    
81. 
    
82. release         version         priority
    
83. APT::Default-Release         above /etc/apt/preferences
    
84. stable         1.0         990         900
    
85. testing         1.1         500         400
    
86. unstable         1.2         500         300
    
87. 
    
88. With an APT::Default-Release of "stable" and no /etc/apt/preferences, if you install the package with "apt-get -t testing install foo" you'll get version 1.1 from testing.
    
89. 
    
90. The big problem happens when you run "apt-get upgrade": Version 1.2 from unstable has the same priority as the 1.1 just installed, so 1.1 (testing) is replaced with 1.2 (unstable)!
    
91. 
    
92. I fix this problem by giving testing and unstable different priorities. With the explicit PINs from the above /etc/apt/preferences, version 1.2 from unstable has priority 300 compared to testing's 400, so the version from testing remains installed.
    
93. 
    
94. The pin of other Debian releases at priority -1 is only a bit of defensiveness. This doesn't affect any Debian sources that I know of (since they're all stable, testing, or unstable), so if a new Debian source is added I'll have to decide what priority to give it. Without this pin it'd come in at the default priority of 500.
    
95. Using Non-Debian Sources
    
96. 
    
97. If you're using non-Debian sources, you've got the same problem, only more so because there's no natural ordering as there is with Debian's stable -> testing -> unstable. Without explicitly listing them in /etc/apt/preferences, they're all at priority 500, so a package installed from one source can be replaced by a higher version supplied by a different source.
    
98. 
    
99. A partial fix for this is to pin each source at a different priority. Eg,
    
100. 
     
101. Package: *
     
102. Pin: origin marillat.free.fr
     
103. Pin-Priority: 600
     
104. 
     
105. Package: *
     
106. Pin: origin www.ibiblio.org
     
107. Pin-Priority: 610
     
108. 
     
109. Package: *
     
110. Pin: origin www.argon.org
     
111. Pin-Priority: 620
     
112. 
     
113. These settings would mean that a package installed from www.argon.org wouldn't automatically be replaced with one from the other two, and one from www.ibiblio.org wouldn't be replaced with one from marillat.free.fr.
     
114. 
     
115. Working in the other direction the packages would still be replaced, however: If you've installed a package from www.ibiblio.org and a newer version becomes available from www.argon.org, apt-get will upgrade to it. The only way I know of to prevent that is to explicitly pin the package to the source via /etc/apt/preferences.
     
116. 
     
117. Roderick Schertler <roderick@argon.org>
     
118. http://www.argon.org/~roderick/
     

复制代码

suheng

非常不错，正需要这个。
谢谢拉哈。