在線升級內核版本

背景

我們知道在很多的情況下，會多內核的版本進行要求。這時候就需要我們對內核的版本進行升級。最簡單的方式就是重新安裝一個內核版本的虛擬機。但是這種方式太過於繁瑣，本章主要介紹兩種在線升級的方式。

查看內核版本

uname -mrs

輸出如下：

Linux 4.4.0-62-generic x86_64

可知當前的內核版本爲4.4.0，並且 CPU爲X86架構64位。其中我們升級內核時，架構和位數不要搞錯了。

方法一：通過apt命令安裝升級內核

1. 通過apt-cache search linux-generic查看當前可用的內核版本。
   命令輸出的結果如下：

linux-generic - Complete Generic Linux kernel and headers
 linux-generic-lts-utopic - Complete Generic Linux kernel and headers (dummy transitional package)
 linux-generic-lts-vivid - Complete Generic Linux kernel and headers (dummy transitional package)
 linux-generic-lts-wily - Complete Generic Linux kernel and headers (dummy transitional package)
 linux-generic-lts-xenial - Complete Generic Linux kernel and headers (dummy transitional package)
 linux-image-4.4.0-21-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-extra-4.4.0-21-generic - Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP
 linux-generic-hwe-16.04 - Complete Generic Linux kernel and headers
 linux-generic-hwe-16.04-edge - Complete Generic Linux kernel and headers
 linux-image-4.10.0-14-generic - Linux kernel image for version 4.10.0 on 64 bit x86 SMP
 linux-image-4.10.0-19-generic - Linux kernel image for version 4.10.0 on 64 bit x86 SMP
 linux-image-4.10.0-27-generic - Linux kernel image for version 4.10.0 on 64 bit x86 SMP
 linux-image-4.10.0-28-generic - Linux kernel image for version 4.10.0 on 64 bit x86 SMP
 linux-image-4.10.0-30-generic - Linux kernel image for version 4.10.0 on 64 bit x86 SMP
 linux-image-4.10.0-32-generic - Linux kernel image for version 4.10.0 on 64 bit x86 SMP
 linux-image-4.11.0-13-generic - Linux kernel image for version 4.11.0 on 64 bit x86 SMP
 linux-image-4.11.0-14-generic - Linux kernel image for version 4.11.0 on 64 bit x86 SMP
 linux-image-4.4.0-22-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-24-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-28-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-31-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-34-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-36-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-38-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-42-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-43-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-45-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-47-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-51-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-53-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-57-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-59-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-62-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-63-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-64-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-66-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-67-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-70-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-71-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-72-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-75-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-77-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-78-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-79-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-81-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-83-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP
 linux-image-4.4.0-87-generic - Linux kernel image for version 4.4.0 on 64 bit x86  SMP
 linux-image-extra-4.10.0-14-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-19-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-20-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-21-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-22-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-24-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-26-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-27-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-28-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-30-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.10.0-32-generic - Linux kernel extra modules for version 4.10.0 on 64 bit x86 SMP
 linux-image-extra-4.11.0-13-generic - Linux kernel extra modules for version 4.11.0 on 64 bit x86 SMP
 linux-image-extra-4.11.0-14-generic - Linux kernel extra modules for version 4.11.0 on 64 bit x86 SMP

大致如上圖所示，我們可知當前的最新的內核版本號是4.11.0-14。其實，我們有時並不需要升級到最新的內核版本。升級到大於目標版本即可。

2.安裝指定的內核版本

執行下面的命令：

sudo apt-get install linux-image-4.11.0-14-generic,其中linux-image-4.11.0-14-generic指定的是內核版本。

命令輸出大致如下：

正在讀取軟件包列表... 完成
 正在分析軟件包的依賴關係樹
 正在讀取狀態信息... 完成
 下列軟件包是自動安裝的並且現在不需要了：
 gyp javascript-common libjs-inherits libjs-jquery libjs-node-uuid libjs-underscore libnvpair1linux libssl-dev libssl-doc libuutil1linux libuv1-dev
 libzfs2linux libzpool2linux python-pkg-resources zfs-doc zlib1g-dev
 使用'apt autoremove'來卸載它(它們)。
 建議安裝：
 fdutils linux-tools linux-headers-4.11.0-14-generic
 下列【新】軟件包將被安裝：
 linux-image-4.11.0-14-generic
 升級了 0 個軟件包，新安裝了 1 個軟件包，要卸載 0 個軟件包，有 5 個軟件包未被升級。
 需要下載 20.4 MB 的歸檔。
 解壓縮後會消耗 70.7 MB 的額外空間。
 獲取:1 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 linux-image-4.11.0-14-generic amd64 4.11.0-14.20~16.04.1 [20.4 MB]
 已下載 20.4 MB，耗時 22秒 (894 kB/s)
 正在選中未選擇的軟件包 linux-image-4.11.0-14-generic。
 (正在讀取數據庫 ... 系統當前共安裝有 67751 個文件和目錄。)
 正準備解包 .../linux-image-4.11.0-14-generic_4.11.0-14.20~16.04.1_amd64.deb  ...
 Done.
 正在解包 linux-image-4.11.0-14-generic (4.11.0-14.20~16.04.1) ...
 正在設置 linux-image-4.11.0-14-generic (4.11.0-14.20~16.04.1) ...
 Running depmod.
 update-initramfs: deferring update (hook will be called later)
 Examining /etc/kernel/postinst.d.
 run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 4.11.0-14-generic /boot/vmlinuz-4.11.0-14-generic
 run-parts: executing /etc/kernel/postinst.d/initramfs-tools 4.11.0-14-generic /boot/vmlinuz-4.11.0-14-generic
 update-initramfs: Generating /boot/initrd.img-4.11.0-14-generic
 W: mdadm: /etc/mdadm/mdadm.conf defines no arrays.
 run-parts: executing /etc/kernel/postinst.d/unattended-upgrades 4.11.0-14-generic /boot/vmlinuz-4.11.0-14-generic
 run-parts: executing /etc/kernel/postinst.d/update-notifier 4.11.0-14-generic /boot/vmlinuz-4.11.0-14-generic
 run-parts: executing /etc/kernel/postinst.d/zz-update-grub 4.11.0-14-generic /boot/vmlinuz-4.11.0-14-generic
 Generating grub configuration file ...
 Found linux image: /boot/vmlinuz-4.11.0-14-generic
 Found initrd image: /boot/initrd.img-4.11.0-14-generic
 Found linux image: /boot/vmlinuz-4.4.0-62-generic
 Found initrd image: /boot/initrd.img-4.4.0-62-generic
 done

3. 重啓系統

reboot
4. 查看當前系統的內核版本

uname -mrs,有時第一次重啓，內核的版本並沒有發生改變，你可以嘗試再重啓一次。

該方法主要是用於能夠聯網的環境，並且成功率並不是很高。如果當你的環境不能聯網，或者第一種方式不成功，你可以考慮使用第二種方式。

方法二：通過下載最新內核deb包安裝內核

1. 從https://kernel.ubuntu.com/~kernel-ppa/mainline/中找到你目標的內核版本，之後進去查看相應的deb文件。
2. 下載對應的deb文件。其中需要注意的是架構以及版本。架構就是ARM，X86,MIPS或PowerPC系列。其中的版本有generic和lowlatency兩個版本，我建議選擇generic版本。其中all是必選的。比如我選擇5.20的版本內核，需要下載以下文件：

linux-headers-5.2.0-050200_5.2.0-050200.201907231526_all.deb
linux-headers-5.2.0-050200-generic_5.2.0-050200.201907231526_amd64.deb
linux-image-unsigned-5.2.0-050200-generic_5.2.0-050200.201907231526_amd64.deb
linux-modules-5.2.0-050200-generic_5.2.0-050200.201907231526_amd64.deb

3. 安裝下載的.deb包
   sudo dpkg -i *.db
4. 重啓系統
   reboot