Hit and Get from sudo apt update 的长列表

Question

为什么在 期间多次重复获得类似的包裹sudo apt update？这是正常的吗？之前，我注意到总共只有 5 到 7 个 Hit 或 Get。最近，我注意到这个更新列表似乎越来越长。

Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease                                                    
Hit:2 http://archive.canonical.com/ubuntu bionic InRelease                                                 
Get:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]                                                                                               
Get:7 http://archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]     
Get:8 http://archive.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]     
Get:9 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages [728 kB]
Get:10 http://archive.ubuntu.com/ubuntu bionic-updates/main i386 Packages [580 kB]
Get:11 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 DEP-11 Metadata [285 kB]
Get:12 http://archive.ubuntu.com/ubuntu bionic-updates/main DEP-11 48x48 Icons [70.9 kB]                                                                                                                          
Get:13 http://archive.ubuntu.com/ubuntu bionic-updates/main DEP-11 64x64 Icons [140 kB]                                                                                                                           
Get:14 http://archive.ubuntu.com/ubuntu bionic-updates/universe amd64 DEP-11 Metadata [253 kB]                                                                                                                    
Get:15 http://archive.ubuntu.com/ubuntu bionic-updates/universe DEP-11 48x48 Icons [209 kB]                                                                                                                       
Get:16 http://archive.ubuntu.com/ubuntu bionic-updates/universe DEP-11 64x64 Icons [452 kB]                                                                                                                       
Get:17 http://archive.ubuntu.com/ubuntu bionic-updates/multiverse amd64 DEP-11 Metadata [2,468 B]                                                                                                                 
Get:18 http://archive.ubuntu.com/ubuntu bionic-backports/universe amd64 DEP-11 Metadata [7,924 B]                                                                                                                 
Get:19 http://archive.ubuntu.com/ubuntu bionic-security/main i386 Packages [368 kB]                                                                                                                               
Get:20 http://archive.ubuntu.com/ubuntu bionic-security/main amd64 Packages [502 kB]                                                                                                                              
Get:21 http://archive.ubuntu.com/ubuntu bionic-security/main Translation-en [170 kB]                                                                                                                              
Get:22 http://archive.ubuntu.com/ubuntu bionic-security/main amd64 DEP-11 Metadata [22.6 kB]                                                                                                                      
Get:23 http://archive.ubuntu.com/ubuntu bionic-security/main DEP-11 48x48 Icons [10.4 kB]                                                                                                                         
Get:24 http://archive.ubuntu.com/ubuntu bionic-security/main DEP-11 64x64 Icons [31.7 kB]                                                                                                                         
Get:25 http://archive.ubuntu.com/ubuntu bionic-security/restricted amd64 Packages [6,600 B]                                                                                                                       
Get:26 http://archive.ubuntu.com/ubuntu bionic-security/restricted Translation-en [2,840 B]                                                                                                                       
Get:27 http://archive.ubuntu.com/ubuntu bionic-security/universe i386 Packages [590 kB]                                                                                                                           
Get:28 http://archive.ubuntu.com/ubuntu bionic-security/universe amd64 Packages [604 kB]                                                                                                                          
Get:29 http://archive.ubuntu.com/ubuntu bionic-security/universe Translation-en [201 kB]                                                                                                                          
Get:30 http://archive.ubuntu.com/ubuntu bionic-security/universe amd64 DEP-11 Metadata [42.1 kB]                                                                                                                  
Get:31 http://archive.ubuntu.com/ubuntu bionic-security/universe DEP-11 64x64 Icons [116 kB]                                                                                                                      
Get:32 http://archive.ubuntu.com/ubuntu bionic-security/multiverse amd64 DEP-11 Metadata [2,464 B]                                                                                                                
Fetched 5,652 kB in 23s (245 kB/s)                                                                                                                                                                                
Reading package lists... Done

更新：

我刚刚又跑sudo apt update了。这一次，只有 8 个 Hit & Get 参与。为什么有时需要如此长的更新而有时需要更短的更新？

Hit:1 http://archive.canonical.com/ubuntu bionic InRelease                                                 
Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease                                                                                    
Hit:5 http://archive.ubuntu.com/ubuntu bionic-updates InRelease                                                                              
Hit:7 http://archive.ubuntu.com/ubuntu bionic-backports InRelease                                                  
Hit:8 http://archive.ubuntu.com/ubuntu bionic-security InRelease                
Fetched 1,310 B in 2s (579 B/s)                      
Reading package lists... Done
Building dependency tree       
Reading state information... Done  

Answer 1

这是正常的，apt正在为每个配置的存储库下载更新的包列表、元数据、图标、翻译。“Hit”表示文件自上次下载后未更改，“Get”表示apt已下载并已下载。

你的第二次运行只检查了InRelease文件；这些包含apt update可能下载的各种其他索引的索引和校验和，并允许apt确定与您系统上的当前内容相比是否有任何更改。如果没有任何变化，它不会下载任何其他内容。您也可以在第一次运行时看到这一点：前两个InRelease文件没有更改，因此没有为这些存储库下载任何其他文件。