ubuntu系统原版本20.04，服务器dell T40.
执行apt update后，再执行apt upgrade。
apt update执行成功，但apt upgrade执行中断，提示如下：
Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Hit http://mirrors.aliyun.com/ubuntu focal InRelease
Hit http://mirrors.aliyun.com/ubuntu focal-updates InRelease
Hit http://mirrors.aliyun.com/ubuntu focal-backports InRelease
Hit http://mirrors.aliyun.com/ubuntu focal-security InRelease
Fetched 0 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
You are using pam_tally or pam_tally2 in your configuration.
The pam_tally and pam_tally2 modules have been removed from PAM. You
are using one of these modules in your PAM configuration in
/etc/pam.d. You must remove the uses of these modules before PAM can
be upgraded; including these modules in your PAM configuration after
the upgrade will stop users from being able to log into the system.
Consider the pam_faillock module as a replacement for pam_tally.
Restoring original system state
进入/etc/pam.d目录
使用命令：
grep pam *
将所有pam相关的配置行使用#注释掉。
保存文件，再次执行apt upgrade。
运行成功。
