Centos7转自源网站
http://www.hostloc.com/thread-342505-1-1.html
Debian8转自源网站
http://www.awkxy.com/archives/721
 

Centos7
先把/etc/sysctl.conf 文件中 关于 net.ipv4.tcp_congestion_control的配置注释掉。（Azure的CentOS 7本来就没有）
wget http://mirrors.kernel.org/debian/pool/main/l/linux/linux-image-4.13.0-1-amd64_4.13.4-1_amd64.deb
ar x linux-image-4.13.0-1-amd64_4.13.4-1_amd64.deb
tar -Jxf data.tar.xz
install -m644 boot/vmlinuz-4.13.0-1-amd64 /boot/vmlinuz-4.13.0-1-amd64
cp -Rav lib/modules/4.13.0-1-amd64 /lib/modules
depmod -a 4.13.0-1-amd64
dracut -f -v –hostonly -k ‘/lib/modules/4.13.0-1-amd64’ /boot/initramfs-4.13.0-1-amd64.img 4.13.0-1-amd64
grub2-mkconfig -o /boot/grub2/grub.cfg
#开启bbr
echo “net.core.default_qdisc=fq” >> /etc/sysctl.conf
echo “net.ipv4.tcp_congestion_control=bbr” >> /etc/sysctl.conf
#调整内核启动顺序
grub2-set-default “CentOS Linux (4.13.0-1-amd64) 7 (Core)”
grub2-editenv list
grub2-mkconfig -o /boot/grub2/grub.cfg
然后reboot

ubuntu/debian系统
下载新内核:
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.11.2/linux-image-4.11.2-041102-generic_4.11.2-041102.201705201036_amd64.deb
安装内核：
dpkg -i linux-image-4.11.[Tab补全]
删除其他内核:
dpkg -l|grep linux-image
apt-get remove linux-image-4.9.0-040900rc8-generic #删4.11.0以外的旧内核
apt-get remove linux-image-4.11.0-trunk-amd64 #删4.11.0以外的旧内核
更新 grub 系统引导文件并重启（Azure虚机执行update-grub报错时看下面）
update-grub
reboot
开启BBR
echo “net.core.default_qdisc=fq” >> /etc/sysctl.conf
echo “net.ipv4.tcp_congestion_control=bbr” >> /etc/sysctl.conf
sysctl -p
sysctl net.ipv4.tcp_available_congestion_control
查看下是否有BBR：lsmod | grep bbr

Azure的Debian8 没有dracut
apt-get install dracut
Azure的Debian8 grub安装不全
sudo apt-get update; sudo apt-get install –reinstall grub
mkdir /boot/grub
Linux小技巧
1，查看发行版
lsb_release -a
2，查看内核
cat /proc/version
uname -a
uname -r
3，查看系统位数
file /bin/ls
4，验证BBR
sysctl net.ipv4.tcp_available_congestion_control
sysctl net.ipv4.tcp_congestion_control
 

Displaying an image during boot instead of the default command line scrolling text

This is based on the guide here.
This solution works but there are a few seconds of text shown before the boot image appears.

Install fbi

sudo apt-get install fbi

Copy the splashscreen image to be used

Copy your custom splash image into: /etc/ and name it “splash.png”.
Presumably the resolution to use is 1920x1080px.
Create A Script

sudo nano

Paste the following into the text editor:

#! /bin/sh
### BEGIN INIT INFO
# Provides:          asplashscreen
# Required-Start:
# Required-Stop:
# Should-Start:
# Default-Start:     S
# Default-Stop:
# Short-Description: Show custom splashscreen
# Description:       Show custom splashscreen
### END INIT INFO
do_start () {
    /usr/bin/fbi -T 1 -noverbose -a /etc/splash.png
    exit 0
}
case "$1" in
  start|"")
    do_start
    ;;
  restart|reload|force-reload)
    echo "Error: argument '$1' not supported" >&2
    exit 3
    ;;
  stop)
    # No-op
    ;;
  status)
    exit 0
    ;;
  *)
    echo "Usage: asplashscreen [start|stop]" >&2
    exit 3
    ;;
esac
:

IMPORTANT – If copying and pasting via SSH check it has pasted in correctly (pasting via FiseSSH for us caused the # lines and the esac line to be altered and need modifying back to be correct)
Exit and save the file as: /etc/init.d/asplashscreen
(using a name starting with ‘a’ will ensure it runs first)
Finally make the script executable and install it for init mode:

sudo chmod a+x /etc/init.d/asplashscreen
sudo insserv /etc/init.d/asplashscreen

Thats it:

sudo reboot

Getting Out Of Black Screen

If you get a black screen at the end of booting (if you’ve not setup auto running the GUI etc) use CTRL + ALT + F2 to get the command prompt