docker推到dockerhub私人回购有时推现有的层（ubuntu的基础层）

我正在推迟dockerhub。 我想每次我推它应该是增量的。 但是有时它会再次推动现有的图层。

这里很less按时间排列

// n-th push 1515e3a2aade: Layer already exists fbe2db54eaea: Layer already exists b3194de9c939: Layer already exists abf060fbeb02: Layer already exists bc61dcaa1fb9: Layer already exists 629d3660cc59: Pushed 5f70bf18a086: Pushed 0d81735d8272: Pushed 982549bd6b32: Pushed 8698b31c92d5: Pushed // n+1-th push 5a2c20b22bf1: Pushed 43ba1325889f: Pushed c23b65a5145c: Pushed abf060fbeb02: Layer already exists bc61dcaa1fb9: Layer already exists 629d3660cc59: Layer already exists 5f70bf18a086: Layer already exists 0d81735d8272: Layer already exists 982549bd6b32: Layer already exists 8698b31c92d5: Layer already exists // n+2-th push, notice how layer 8698b31c92d5 and 3 more layers got pushed again 06db42d823c5: Pushed a3575dd784b5: Pushed e04cb41bff92: Pushed abf060fbeb02: Layer already exists bc61dcaa1fb9: Layer already exists 629d3660cc59: Pushed 5f70bf18a086: Layer already exists 0d81735d8272: Pushed 982549bd6b32: Pushed 8698b31c92d5: Pushed 

这里是docker历史第n + 2推

 54ee4d70917c 10 minutes ago /bin/sh -c #(nop) EXPOSE 12000/tcp 12001/tcp 0 B 8ae93e68a93a 10 minutes ago /bin/sh -c #(nop) ENTRYPOINT &{["./nexus"]} 0 B 7644eba33444 10 minutes ago /bin/sh -c #(nop) COPY multi:609730bd4dcd2093 571 kB ac87f067a414 10 minutes ago /bin/sh -c #(nop) COPY multi:7b816c50da4eff99 10.84 MB 52ad31e3d4fb 10 minutes ago /bin/sh -c #(nop) COPY file:dc5824a16ae1ce7e8 14.9 MB 841eb28ef938 44 hours ago /bin/sh -c #(nop) WORKDIR /prod/bin 0 B b167f0cca892 44 hours ago /bin/sh -c mkdir -p /prod/socketio/asset/ 0 B c9c427a1999d 44 hours ago /bin/sh -c mkdir -p /prod/eval/bin 0 B 9bad1ce6d92c 44 hours ago /bin/sh -c mkdir -p /prod/bin 0 B 3876b81b5a81 3 weeks ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0 B <missing> 3 weeks ago /bin/sh -c sed -i 's/^#\s*\(deb.*universe\)$/ 1.895 kB <missing> 3 weeks ago /bin/sh -c echo '#!/bin/sh' > /usr/sbin/polic 194.5 kB <missing> 3 weeks ago /bin/sh -c #(nop) ADD file:7ce20ce3daa6af21db 187.7 MB 

任何想法为什么层<missing> 3 weeks ago /bin/sh -c #(nop) ADD file:7ce20ce3daa6af21db 187.7 MB （8698b31c92d5）再次推送？

编辑：我重新启动docker主机（docker机重启默认），这是否重要？ 在推送之前不应该使用docker push从服务器获取现有层哈希列表？