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Re: Import/Export as a fast way to purge files from Git?

From
Lars Schneider <larsxschneider@gmail.com>
Date
Sep 23, 2018, 15:58 UTC
Message-ID
<DE9CF60B-7DCB-4B82-9C96-663E145CAD56@gmail.com>
In-Reply-To
<CAPig+cTLjThK4CVzfgV=Uk5OumpjhaQD_YNXmg7pNtkkUFiiyQ@mail.gmail.com>
Show 17 quoted lines
> On Sep 23, 2018, at 4:55 PM, Eric Sunshine <sunshine@sunshineco.com> wrote:
> 
> On Sun, Sep 23, 2018 at 9:05 AM Lars Schneider <larsxschneider@gmail.com> wrote:
>> I recently had to purge files from large Git repos (many files, many commits).
>> The usual recommendation is to use `git filter-branch --index-filter` to purge
>> files. However, this is *very* slow for large repos (e.g. it takes 45min to
>> remove the `builtin` directory from git core). I realized that I can remove
>> files *way* faster by exporting the repo, removing the file references,
>> and then importing the repo (see Perl script below, it takes ~30sec to remove
>> the `builtin` directory from git core). Do you see any problem with this
>> approach?
> 
> A couple comments:
> 
> For purging files from a history, take a look at BFG[1] which bills
> itself as "a simpler, faster alternative to git-filter-branch for
> cleansing bad data out of your Git repository history".

Yes, BFG is great. Unfortunately, it requires Java which is not available on every system I have to work with. I required a solution that would work in every Git environment. Hence the Perl script :-)

> The approach of exporting to a fast-import stream, modifying the
> stream, and re-importing is quite reasonable.
Thanks for the confirmation!
Show 5 quoted lines
> However, rather than
> re-inventing, take a look at reposurgeon[2], which allows you to do
> major surgery on fast-import streams. Not only can it purge files from
> a repository, but it can slice, dice, puree, and saute pretty much any
> attribute of a repository.
Wow. Reposurgeon looks very interesting. Thanks a lot for the pointer!

Cheers, Lars

> [1]: https://rtyley.github.io/bfg-repo-cleaner/
> [2]: http://www.catb.org/esr/reposurgeon/
Previous: Eric SunshineNext: brian m. carlson
Message 3 of 90 in “Import/Export as a fast way to purge files from Git?”
  1. Lars SchneiderSep 23, 2018
  2. Eric SunshineSep 23, 2018
  3. Lars SchneiderSep 23, 2018
  4. brian m. carlsonSep 23, 2018
  5. Jeff KingSep 23, 2018
  6. Elijah NewrenSep 24, 2018
  7. Lars SchneiderOct 31, 2018
  8. Elijah NewrenNov 1, 2018
  9. 00/10 fast export and import fixes and featuresElijah Newren, Nov 11, 2018
  10. 01/10 git-fast-import.txt: fix documentation for --quiet optionElijah Newren, Nov 11, 2018
  11. Jeff KingNov 11, 2018
  12. 02/10 git-fast-export.txt: clarify misleading documentation about rev-list argsElijah Newren, Nov 11, 2018
  13. Jeff KingNov 11, 2018
  14. Elijah NewrenNov 11, 2018
  15. Elijah NewrenNov 13, 2018
  16. Jonathan NiederNov 13, 2018
  17. Elijah NewrenNov 14, 2018
  18. 03/10 fast-export: use value from correct enumElijah Newren, Nov 11, 2018
  19. Jeff KingNov 11, 2018
  20. Ævar Arnfjörð BjarmasonNov 11, 2018
  21. Ævar Arnfjörð BjarmasonNov 12, 2018
  22. Jeff KingNov 12, 2018
  23. 04/10 fast-export: avoid dying when filtering by paths and old tags existElijah Newren, Nov 11, 2018
  24. Jeff KingNov 11, 2018
  25. Elijah NewrenNov 11, 2018
  26. Jeff KingNov 12, 2018
  27. brian m. carlsonNov 12, 2018
  28. Jeff KingNov 13, 2018
  29. 05/10 fast-export: move commit rewriting logic into a function for reuseElijah Newren, Nov 11, 2018
  30. Jeff KingNov 11, 2018
  31. 06/10 fast-export: when using paths, avoid corrupt stream with non-existent markElijah Newren, Nov 11, 2018
  32. Jeff KingNov 11, 2018
  33. Elijah NewrenNov 11, 2018
  34. Jeff KingNov 12, 2018
  35. Elijah NewrenNov 12, 2018
  36. 07/10 fast-export: ensure we export requested refsElijah Newren, Nov 11, 2018
  37. Jeff KingNov 11, 2018
  38. Elijah NewrenNov 11, 2018
  39. 08/10 fast-export: add --reference-excluded-parents optionElijah Newren, Nov 11, 2018
  40. Jeff KingNov 11, 2018
  41. 09/10 fast-export: add a --show-original-ids option to show original namesElijah Newren, Nov 11, 2018
  42. Jeff KingNov 11, 2018
  43. Elijah NewrenNov 11, 2018
  44. Jeff KingNov 12, 2018
  45. Elijah NewrenNov 12, 2018
  46. Jeff KingNov 12, 2018
  47. 10/10 fast-export: add --always-show-modify-after-renameElijah Newren, Nov 11, 2018
  48. Jeff KingNov 11, 2018
  49. Elijah NewrenNov 11, 2018
  50. Jeff KingNov 12, 2018
  51. Elijah NewrenNov 12, 2018
  52. Jeff KingNov 13, 2018
  53. Elijah NewrenNov 13, 2018
  54. Jeff KingNov 14, 2018
  55. Jeff KingNov 11, 2018
  56. Elijah NewrenNov 11, 2018
  57. Jeff KingNov 12, 2018
  58. 00/11 fast export and import fixes and featuresElijah Newren, Nov 14, 2018
  59. 07/11 fast-export: ensure we export requested refsElijah Newren, Nov 14, 2018
  60. 11/11 fast-export: add --always-show-modify-after-renameElijah Newren, Nov 14, 2018
  61. 01/11 git-fast-import.txt: fix documentation for --quiet optionElijah Newren, Nov 14, 2018
  62. 10/11 fast-export: add a --show-original-ids option to show original namesElijah Newren, Nov 14, 2018
  63. 05/11 fast-export: move commit rewriting logic into a function for reuseElijah Newren, Nov 14, 2018
  64. 09/11 fast-import: remove unmaintained duplicate documentationElijah Newren, Nov 14, 2018
  65. 04/11 fast-export: avoid dying when filtering by paths and old tags existElijah Newren, Nov 14, 2018
  66. SZEDER GáborNov 14, 2018
  67. Elijah NewrenNov 14, 2018
  68. 06/11 fast-export: when using paths, avoid corrupt stream with non-existent markElijah Newren, Nov 14, 2018
  69. 08/11 fast-export: add --reference-excluded-parents optionElijah Newren, Nov 14, 2018
  70. SZEDER GáborNov 14, 2018
  71. Elijah NewrenNov 14, 2018
  72. 03/11 fast-export: use value from correct enumElijah Newren, Nov 14, 2018
  73. 02/11 git-fast-export.txt: clarify misleading documentation about rev-list argsElijah Newren, Nov 14, 2018
  74. Jeff KingNov 14, 2018
  75. 00/11 fast export and import fixes and featuresElijah Newren, Nov 16, 2018
  76. 03/11 git-fast-export.txt: clarify misleading documentation about rev-list argsElijah Newren, Nov 16, 2018
  77. 07/11 fast-export: when using paths, avoid corrupt stream with non-existent markElijah Newren, Nov 16, 2018
  78. 01/11 fast-export: convert sha1 to oidElijah Newren, Nov 16, 2018
  79. 02/11 git-fast-import.txt: fix documentation for --quiet optionElijah Newren, Nov 16, 2018
  80. 08/11 fast-export: ensure we export requested refsElijah Newren, Nov 16, 2018
  81. 09/11 fast-export: add --reference-excluded-parents optionElijah Newren, Nov 16, 2018
  82. 10/11 fast-import: remove unmaintained duplicate documentationElijah Newren, Nov 16, 2018
  83. 06/11 fast-export: move commit rewriting logic into a function for reuseElijah Newren, Nov 16, 2018
  84. 11/11 fast-export: add a --show-original-ids option to show original namesElijah Newren, Nov 16, 2018
  85. SZEDER GáborNov 16, 2018
  86. 05/11 fast-export: avoid dying when filtering by paths and old tags existElijah Newren, Nov 16, 2018
  87. 04/11 fast-export: use value from correct enumElijah Newren, Nov 16, 2018
  88. Jeff KingNov 16, 2018
  89. Ævar Arnfjörð BjarmasonNov 12, 2018
  90. Elijah NewrenNov 12, 2018

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