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Git chokes on large file

From
Dale R. Worley <worley@alum.mit.edu>
Date
May 27, 2014, 16:47 UTC
Message-ID
<201405271647.s4RGlDJc024596@hobgoblin.ariadne.com>

I've discovered a problem using Git. It's not clear to me what the "correct" behavior should be, but it seems to me that Git is failing in an undesirable way.

The problem arises when trying to handle a very large file. For example:

    $ git --version
    git version 1.8.3.1
    $ mkdir $$
    $ cd $$
    $ git init
    Initialized empty Git repository in /common/not-replicated/worley/temp/5627/.git/
    $ truncate --size=20G big_file
    $ ls -l
    total 0
    -rw-rw-r--. 1 worley worley 21474836480 May 27 11:59 big_file
    $ time git add big_file
    real	4m48.752s
    user	4m31.295s
    sys	0m16.747s
    $
At this point, either 'git fsck' or 'git commit' fails:
    $ git fsck --full --strict
    notice: HEAD points to an unborn branch (master)
    Checking object directories: 100% (256/256), done.
    fatal: Out of memory, malloc failed (tried to allocate 21474836481 bytes)
    $ git commit -m Test.
    [master (root-commit) 3df3655] Test.
    fatal: Out of memory, malloc failed (tried to allocate 21474836481 bytes)

The central problem is that one can accidentally add a file that leaves the repository in a "broken" state, where various normal commands simply don't work. The most worrying aspect is that "git fsck" fails -- of all the commands, the one that verifies the validity of the repository (and diagnoses errors) should be the most robust!

Even doing a 'git reset' does not put the repository in a state where 'git fsck' will complete:

    $ git reset
    $ git fsck --full --strict
    notice: HEAD points to an unborn branch (master)
    Checking object directories: 100% (256/256), done.
    fatal: Out of memory, malloc failed (tried to allocate 21474836481 bytes)
Dale
Next: Duy Nguyen
Message 1 of 49 in “Git chokes on large file”
  1. Dale R. WorleyMay 27, 2014
  2. Duy NguyenMay 28, 2014
  3. Junio C HamanoMay 28, 2014
  4. Dale R. WorleyMay 28, 2014
  5. Dale R. WorleyMay 28, 2014
  6. David LangMay 28, 2014
  7. Dale R. WorleyMay 28, 2014
  8. David LangMay 28, 2014
  9. Dale R. WorleyMay 29, 2014
  10. Junio C HamanoMay 28, 2014
  11. David LangMay 28, 2014
  12. 1/4 wrapper.c: introduce gentle xmallocz that does not die()Nguyễn Thái Ngọc Duy, May 29, 2014
  13. 2/4 fsck: do not die when not enough memory to examine a pack entryNguyễn Thái Ngọc Duy, May 29, 2014
  14. 3/4 diff.c: allow to pass more flags to diff_populate_filespecNguyễn Thái Ngọc Duy, May 29, 2014
  15. 4/4 diff: mark any file larger than core.bigfilethreshold binaryNguyễn Thái Ngọc Duy, May 29, 2014
  16. Thomas BraunJun 19, 2014
  17. Duy NguyenJun 23, 2014
  18. Thomas BraunJun 23, 2014
  19. 1/4 wrapper.c: introduce gentle xmallocz that does not die()Nguyễn Thái Ngọc Duy, Jun 24, 2014
  20. 2/4 fsck: do not die when not enough memory to examine a pack entryNguyễn Thái Ngọc Duy, Jun 24, 2014
  21. Junio C HamanoJun 26, 2014
  22. Duy NguyenJun 29, 2014
  23. 3/4 diff.c: allow to pass more flags to diff_populate_filespecNguyễn Thái Ngọc Duy, Jun 24, 2014
  24. 4/4 diff: mark any file larger than core.bigfilethreshold binaryNguyễn Thái Ngọc Duy, Jun 24, 2014
  25. Junio C HamanoJun 26, 2014
  26. Thomas BraunJun 27, 2014
  27. Duy NguyenJun 29, 2014
  28. 0/6 Large file improvementsNguyễn Thái Ngọc Duy, Aug 13, 2014
  29. 1/6 wrapper.c: introduce gentle xmalloc(z) that does not die()Nguyễn Thái Ngọc Duy, Aug 13, 2014
  30. Junio C HamanoAug 14, 2014
  31. 2/6 sha1_file.c: do not die failing to malloc in unpack_compressed_entryNguyễn Thái Ngọc Duy, Aug 13, 2014
  32. Junio C HamanoAug 13, 2014
  33. 3/6 unpack-objects: continue when fail to malloc due to large objectsNguyễn Thái Ngọc Duy, Aug 13, 2014
  34. Junio C HamanoAug 14, 2014
  35. Duy NguyenAug 15, 2014
  36. 4/6 diff.c: allow to pass more flags to diff_populate_filespecNguyễn Thái Ngọc Duy, Aug 13, 2014
  37. 5/6 diff --stat: mark any file larger than core.bigfilethreshold binaryNguyễn Thái Ngọc Duy, Aug 13, 2014
  38. Eric SunshineAug 13, 2014
  39. 6/6 diff: shortcut for diff'ing two binary SHA-1 objectsNguyễn Thái Ngọc Duy, Aug 13, 2014
  40. Junio C HamanoAug 14, 2014
  41. Duy NguyenAug 15, 2014
  42. Junio C HamanoAug 14, 2014
  43. 0/5 Large file improvementsNguyễn Thái Ngọc Duy, Aug 16, 2014
  44. 1/5 wrapper.c: introduce gentle xmallocz that does not die()Nguyễn Thái Ngọc Duy, Aug 16, 2014
  45. 2/5 sha1_file.c: do not die failing to malloc in unpack_compressed_entryNguyễn Thái Ngọc Duy, Aug 16, 2014
  46. 3/5 diff.c: allow to pass more flags to diff_populate_filespecNguyễn Thái Ngọc Duy, Aug 16, 2014
  47. 4/5 diff --stat: mark any file larger than core.bigfilethreshold binaryNguyễn Thái Ngọc Duy, Aug 16, 2014
  48. 5/5 diff: shortcut for diff'ing two binary SHA-1 objectsNguyễn Thái Ngọc Duy, Aug 16, 2014
  49. Thomas BraunMay 28, 2014

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