几天前我将服务器从 16.04 更新到 18.04，今天我发现了这一点：
19 packages can be updated.
18 updates are security updates.
我做到了：
sudo apt-get update
sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
libapache2-mod-php7.2 php7.2-bcmath php7.2-bz2 php7.2-cgi php7.2-cli php7.2-common php7.2-fpm php7.2-gd php7.2-intl php7.2-json php7.2-mbstring php7.2-mysql php7.2-opcache php7.2-readline php7.2-xml php7.2-xmlrpc php7.2-zip
The following packages will be upgraded:
php7.2 snap-confine snapd ubuntu-core-launcher
4 upgraded, 0 newly installed, 0 to remove and 17 not upgraded.
Need to get 12.2 MB of archives.
After this operation, 21.5 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://archive.ubuntu.com/ubuntu bionic-updates/universe amd64 ubuntu-core-launcher amd64 2.32.8+18.04 [1,644 B]
Get:2 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 snapd amd64 2.32.8+18.04 [12.2 MB]
Get:3 http://archive.ubuntu.com/ubuntu bionic-updates/universe amd64 snap-confine amd64 2.32.8+18.04 [1,792 B]
Get:4 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 php7.2 all 7.2.5-0ubuntu0.18.04.1 [9,240 B]
Fetched 12.2 MB in 2s (6,527 kB/s)
(Reading database ... 81195 files and directories currently installed.)
Preparing to unpack .../ubuntu-core-launcher_2.32.8+18.04_amd64.deb ...
Unpacking ubuntu-core-launcher (2.32.8+18.04) over (2.32.5+18.04) ...
Preparing to unpack .../snapd_2.32.8+18.04_amd64.deb ...
Unpacking snapd (2.32.8+18.04) over (2.32.5+18.04) ...
Preparing to unpack .../snap-confine_2.32.8+18.04_amd64.deb ...
Unpacking snap-confine (2.32.8+18.04) over (2.32.5+18.04) ...
Preparing to unpack .../php7.2_7.2.5-0ubuntu0.18.04.1_all.deb ...
Unpacking php7.2 (7.2.5-0ubuntu0.18.04.1) over (7.2.4-1+ubuntu16.04.1+deb.sury.org+1) ...
Setting up snapd (2.32.8+18.04) ...
Created symlink /etc/systemd/system/multi-user.target.wants/snapd.seeded.service → /lib/systemd/system/snapd.seeded.service.
Created symlink /etc/systemd/system/cloud-final.service.wants/snapd.seeded.service → /lib/systemd/system/snapd.seeded.service.
snapd.snap-repair.service is a disabled or a static unit, not starting it.
Setting up php7.2 (7.2.5-0ubuntu0.18.04.1) ...
Processing triggers for man-db (2.8.3-2) ...
Setting up ubuntu-core-launcher (2.32.8+18.04) ...
Setting up snap-confine (2.32.8+18.04) ...
现在：
18 packages can be updated.
17 updates are security updates.
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
libapache2-mod-php7.2 php7.2-bcmath php7.2-bz2 php7.2-cgi php7.2-cli php7.2-common php7.2-fpm php7.2-gd php7.2-intl php7.2-json php7.2-mbstring php7.2-mysql php7.2-opcache php7.2-readline php7.2-xml php7.2-xmlrpc php7.2-zip
0 upgraded, 0 newly installed, 0 to remove and 17 not upgraded.
这怎么可能？我错过了什么？几天前更新了 Web 服务器，更新内容是有关 PHP 的，这对于 Web 服务器来说非常重要。我该怎么办？我应该怎么做？他们会稍后与其他更新一起更新吗？版本更新几天后出现这种行为是否正常？我的服务器在 Vultr，也许 Vultr 中缺少了某些东西？
答案1
我的第一个问题是，您是否已重新启动系统以确保已应用所有以前的更新（需要注销操作系统）？
其次，你尝试过这个命令吗？
sudo apt-get dist-upgrade -y
根据我的经验，所有更新将在一两天内应用于新建的系统，但您可以尝试强制执行。