我已经安装并配置了无人值守升级，但每次运行 apt-get upgrade 时，我仍然看到有新的软件包等待安装。我甚至等了 2 周才让它们自动安装，但这种情况从未发生过。
这是我的配置文件：
/etc/apt/apt.conf.d/50unattended-upgrades
Unattended-Upgrade::Allowed-Origins {
"${distro_id}:${distro_codename}";
"${distro_id}:${distro_codename}-security";
// Extended Security Maintenance; doesn't necessarily exist for
// every release and this system may not have it installed, but if
// available, the policy for updates is such that unattended-upgrades
// should also install from here by default.
"${distro_id}ESM:${distro_codename}";
"${distro_id}:${distro_codename}-updates";
"${distro_id}:${distro_codename}-proposed";
"${distro_id}:${distro_codename}-backports";
};
/etc/apt/apt.conf.d/20auto-upgrades
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";
ls -l /var/lib/apt/periodic/
total 0
uname -a
Linux 2.6.32-openvz-042stab120.18-amd64 #1 SMP Fri Jan 13 10:33:34 MSK 2017 i686 i686 i686 GNU/Linux
cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.5 LTS"
（这是一个服务器）
sudo apt-get 安装无人值守升级
Reading package lists... Done
Building dependency tree
Reading state information... Done
unattended-upgrades is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
如您所见，有 4 个包需要升级，但无人值守升级没有执行任何操作。
sudo apt-get——模拟升级
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
libssl-dev libssl-doc libssl1.0.0 openssl
4 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Inst libssl-doc [1.0.1f-1ubuntu2.26] (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [all])
Inst libssl-dev [1.0.1f-1ubuntu2.26] (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [i386]) []
Inst libssl1.0.0 [1.0.1f-1ubuntu2.26] (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [i386])
Inst openssl [1.0.1f-1ubuntu2.26] (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [i386])
Conf libssl-doc (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [all])
Conf libssl1.0.0 (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [i386])
Conf libssl-dev (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [i386])
Conf openssl (1.0.1f-1ubuntu2.27 Ubuntu:14.04/trusty-security [i386])