Documentation/config/pack.txt

   1 pack.window::
   2         The size of the window used by linkgit:git-pack-objects[1] when no
   3         window size is given on the command line. Defaults to 10.
   4
   5 pack.depth::
   6         The maximum delta depth used by linkgit:git-pack-objects[1] when no
   7         maximum depth is given on the command line. Defaults to 50.
   8         Maximum value is 4095.
   9
  10 pack.windowMemory::
  11         The maximum size of memory that is consumed by each thread
  12         in linkgit:git-pack-objects[1] for pack window memory when
  13         no limit is given on the command line.  The value can be
  14         suffixed with "k", "m", or "g".  When left unconfigured (or
  15         set explicitly to 0), there will be no limit.
  16
  17 pack.compression::
  18         An integer -1..9, indicating the compression level for objects
  19         in a pack file. -1 is the zlib default. 0 means no
  20         compression, and 1..9 are various speed/size tradeoffs, 9 being
  21         slowest.  If not set,  defaults to core.compression.  If that is
  22         not set,  defaults to -1, the zlib default, which is "a default
  23         compromise between speed and compression (currently equivalent
  24         to level 6)."
  25 +
  26 Note that changing the compression level will not automatically recompress
  27 all existing objects. You can force recompression by passing the -F option
  28 to linkgit:git-repack[1].
  29
  30 pack.allowPackReuse::
  31         When true or "single", and when reachability bitmaps are
  32         enabled, pack-objects will try to send parts of the bitmapped
  33         packfile verbatim. When "multi", and when a multi-pack
  34         reachability bitmap is available, pack-objects will try to send
  35         parts of all packs in the MIDX.
  36 +
  37 If only a single pack bitmap is available, and `pack.allowPackReuse`
  38 is set to "multi", reuse parts of just the bitmapped packfile. This
  39 can reduce memory and CPU usage to serve fetches, but might result in
  40 sending a slightly larger pack. Defaults to true.
  41
  42 pack.island::
  43         An extended regular expression configuring a set of delta
  44         islands. See "DELTA ISLANDS" in linkgit:git-pack-objects[1]
  45         for details.
  46
  47 pack.islandCore::
  48         Specify an island name which gets to have its objects be
  49         packed first. This creates a kind of pseudo-pack at the front
  50         of one pack, so that the objects from the specified island are
  51         hopefully faster to copy into any pack that should be served
  52         to a user requesting these objects. In practice this means
  53         that the island specified should likely correspond to what is
  54         the most commonly cloned in the repo. See also "DELTA ISLANDS"
  55         in linkgit:git-pack-objects[1].
  56
  57 pack.deltaCacheSize::
  58         The maximum memory in bytes used for caching deltas in
  59         linkgit:git-pack-objects[1] before writing them out to a pack.
  60         This cache is used to speed up the writing object phase by not
  61         having to recompute the final delta result once the best match
  62         for all objects is found.  Repacking large repositories on machines
  63         which are tight with memory might be badly impacted by this though,
  64         especially if this cache pushes the system into swapping.
  65         A value of 0 means no limit. The smallest size of 1 byte may be
  66         used to virtually disable this cache. Defaults to 256 MiB.
  67
  68 pack.deltaCacheLimit::
  69         The maximum size of a delta, that is cached in
  70         linkgit:git-pack-objects[1]. This cache is used to speed up the
  71         writing object phase by not having to recompute the final delta
  72         result once the best match for all objects is found.
  73         Defaults to 1000. Maximum value is 65535.
  74
  75 pack.threads::
  76         Specifies the number of threads to spawn when searching for best
  77         delta matches.  This requires that linkgit:git-pack-objects[1]
  78         be compiled with pthreads otherwise this option is ignored with a
  79         warning. This is meant to reduce packing time on multiprocessor
  80         machines. The required amount of memory for the delta search window
  81         is however multiplied by the number of threads.
  82         Specifying 0 will cause Git to auto-detect the number of CPUs
  83         and set the number of threads accordingly.
  84
  85 pack.indexVersion::
  86         Specify the default pack index version.  Valid values are 1 for
  87         legacy pack index used by Git versions prior to 1.5.2, and 2 for
  88         the new pack index with capabilities for packs larger than 4 GB
  89         as well as proper protection against the repacking of corrupted
  90         packs.  Version 2 is the default.  Note that version 2 is enforced
  91         and this config option is ignored whenever the corresponding pack is
  92         larger than 2 GB.
  93 +
  94 If you have an old Git that does not understand the version 2 `*.idx` file,
  95 cloning or fetching over a non-native protocol (e.g. "http")
  96 that will copy both `*.pack` file and corresponding `*.idx` file from the
  97 other side may give you a repository that cannot be accessed with your
  98 older version of Git. If the `*.pack` file is smaller than 2 GB, however,
  99 you can use linkgit:git-index-pack[1] on the *.pack file to regenerate
 100 the `*.idx` file.
 101
 102 pack.packSizeLimit::
 103         The maximum size of a pack.  This setting only affects
 104         packing to a file when repacking, i.e. the git:// protocol
 105         is unaffected.  It can be overridden by the `--max-pack-size`
 106         option of linkgit:git-repack[1].  Reaching this limit results
 107         in the creation of multiple packfiles.
 108 +
 109 Note that this option is rarely useful, and may result in a larger total
 110 on-disk size (because Git will not store deltas between packs) and
 111 worse runtime performance (object lookup within multiple packs is
 112 slower than a single pack, and optimizations like reachability bitmaps
 113 cannot cope with multiple packs).
 114 +
 115 If you need to actively run Git using smaller packfiles (e.g., because your
 116 filesystem does not support large files), this option may help. But if
 117 your goal is to transmit a packfile over a medium that supports limited
 118 sizes (e.g., removable media that cannot store the whole repository),
 119 you are likely better off creating a single large packfile and splitting
 120 it using a generic multi-volume archive tool (e.g., Unix `split`).
 121 +
 122 The minimum size allowed is limited to 1 MiB. The default is unlimited.
 123 Common unit suffixes of 'k', 'm', or 'g' are supported.
 124
 125 pack.useBitmaps::
 126         When true, git will use pack bitmaps (if available) when packing
 127         to stdout (e.g., during the server side of a fetch). Defaults to
 128         true. You should not generally need to turn this off unless
 129         you are debugging pack bitmaps.
 130
 131 pack.useBitmapBoundaryTraversal::
 132         When true, Git will use an experimental algorithm for computing
 133         reachability queries with bitmaps. Instead of building up
 134         complete bitmaps for all of the negated tips and then OR-ing
 135         them together, consider negated tips with existing bitmaps as
 136         additive (i.e. OR-ing them into the result if they exist,
 137         ignoring them otherwise), and build up a bitmap at the boundary
 138         instead.
 139 +
 140 When using this algorithm, Git may include too many objects as a result
 141 of not opening up trees belonging to certain UNINTERESTING commits. This
 142 inexactness matches the non-bitmap traversal algorithm.
 143 +
 144 In many cases, this can provide a speed-up over the exact algorithm,
 145 particularly when there is poor bitmap coverage of the negated side of
 146 the query.
 147
 148 pack.useSparse::
 149         When true, git will default to using the '--sparse' option in
 150         'git pack-objects' when the '--revs' option is present. This
 151         algorithm only walks trees that appear in paths that introduce new
 152         objects. This can have significant performance benefits when
 153         computing a pack to send a small change. However, it is possible
 154         that extra objects are added to the pack-file if the included
 155         commits contain certain types of direct renames. Default is
 156         `true`.
 157
 158 pack.preferBitmapTips::
 159         When selecting which commits will receive bitmaps, prefer a
 160         commit at the tip of any reference that is a suffix of any value
 161         of this configuration over any other commits in the "selection
 162         window".
 163 +
 164 Note that setting this configuration to `refs/foo` does not mean that
 165 the commits at the tips of `refs/foo/bar` and `refs/foo/baz` will
 166 necessarily be selected. This is because commits are selected for
 167 bitmaps from within a series of windows of variable length.
 168 +
 169 If a commit at the tip of any reference which is a suffix of any value
 170 of this configuration is seen in a window, it is immediately given
 171 preference over any other commit in that window.
 172
 173 pack.writeBitmaps (deprecated)::
 174         This is a deprecated synonym for `repack.writeBitmaps`.
 175
 176 pack.writeBitmapHashCache::
 177         When true, git will include a "hash cache" section in the bitmap
 178         index (if one is written). This cache can be used to feed git's
 179         delta heuristics, potentially leading to better deltas between
 180         bitmapped and non-bitmapped objects (e.g., when serving a fetch
 181         between an older, bitmapped pack and objects that have been
 182         pushed since the last gc). The downside is that it consumes 4
 183         bytes per object of disk space. Defaults to true.
 184 +
 185 When writing a multi-pack reachability bitmap, no new namehashes are
 186 computed; instead, any namehashes stored in an existing bitmap are
 187 permuted into their appropriate location when writing a new bitmap.
 188
 189 pack.writeBitmapLookupTable::
 190         When true, Git will include a "lookup table" section in the
 191         bitmap index (if one is written). This table is used to defer
 192         loading individual bitmaps as late as possible. This can be
 193         beneficial in repositories that have relatively large bitmap
 194         indexes. Defaults to false.
 195
 196 pack.readReverseIndex::
 197         When true, git will read any .rev file(s) that may be available
 198         (see: linkgit:gitformat-pack[5]). When false, the reverse index
 199         will be generated from scratch and stored in memory. Defaults to
 200         true.
 201
 202 pack.writeReverseIndex::
 203         When true, git will write a corresponding .rev file (see:
 204         linkgit:gitformat-pack[5])
 205         for each new packfile that it writes in all places except for
 206         linkgit:git-fast-import[1] and in the bulk checkin mechanism.
 207         Defaults to true.