有時候當你運行一些git命令（比如git pull）的時候，會有如下提示：
Auto packing the repository for optimum performance. You may also run "git gc" manually. See "git help gc" for more information.
翻譯：
自動包裝最佳性能的存儲庫。 你也可以手動運行 ‘get gc’ 。有關更多信息,請參見“git幫助gc”。
當有這個提示的時候，直接運行 ' git gc '，就可以了。
原因：
Git 往磁盤保存對象時默認使用的格式叫松散對象 (loose object) 格式。Git 時不時地將這些對象打包至一個叫 packfile 的二進制文件以節省空間並提高效率。當倉庫中有太多的松散對象則就會提示你運行 ' git gc '。
我們可以運行 ' find .git/objects -type f ' 命令，查看一下 objects 目錄里有多少對象，如下：
$ find .git/objects -type f .git/objects/07/0cc4950ddcd2595a8134d8e560aef2a733e581 .git/objects/13/93d47387301d83214a34883f182cacb717762c .git/objects/1c/1962af2351551af106a46a2bf43543a8bacf52 .git/objects/1c/4c0087a2c81ae4d1a521eddcecbbedc5c90270 .git/objects/36/39f696bdc97385fefb67926cdc0895e3dc5bb3 .git/objects/48/ec12b8a1a0d53d49e80156cfe969e438384da1 .git/objects/52/65597ee5edea6bc415506f097ebe072ef79363 .git/objects/52/86195cdb9c73333e06fb755272030105c50ef3 ... .git/objects/pack/pack-0c73db178d8a396a3ab624b4acf9dda479593691.idx .git/objects/pack/pack-0c73db178d8a396a3ab624b4acf9dda479593691.pack .git/objects/pack/pack-7c6c1af87ebb721211b490eec0ee6d5b49b5b280.idx .git/objects/pack/pack-7c6c1af87ebb721211b490eec0ee6d5b49b5b280.pack
然后在運行 ' git gc ' 命令后，在執行剛才的命令，看下 object 目錄里面還剩下多少對象，如下：
$ git gc Counting objects: 11099, done. Delta compression using up to 4 threads. Compressing objects: 100% (3219/3219), done. Writing objects: 100% (11099/11099), done. Total 11099 (delta 7805), reused 10988 (delta 7712) userName@DST56034 /D/gitProject(master) $ find .git/objects -type f .git/objects/info/packs .git/objects/pack/pack-1ddf288322e0efcb6ca533b685b707ef269ff8f0.idx .git/objects/pack/pack-1ddf288322e0efcb6ca533b685b707ef269ff8f0.pack
相關文章：http://gitbook.liuhui998.com/4_10.html