Resolve the problem of install VirtualBox addon on Fedora

Error message:
Failed to set up service vboxadd, please check the log file
unable to find the sources of your current linux kernel

# sudo dnf update

#sudo dnf install gcc kernel-devel kernel-headers

Restart the Fedora virtual machine and install VirtualBox Addon

Docker study

docker是個應用LXC的utility，可方便建立跨平台的images，執行container。

指令：

docker pull

>Download某個image下來，只後用指令docker images可看到目前擁有的images

docker run -d

>-d, run as daemon. 不會執行完就馬上結束了

Install Ubuntu packages from cdrom

1. mount /dev/cdrom /media/cdrom
2. uncomment the first line of /etc/apt/source.list
   deb xxxx
3. apt-get install xxxxx

防止VPN連線成為預設閘道

Prevent VPN connection become the default gateway

for both IPv4 and IPv6 properties, after clicking the Advanced button, make sure "Use default gateway on remote network" isunchecked.

Prevent VPN proxy

jekyll docker under windows

1. Install Docker Toolbox
2. Startup Docker Terminal
3. Use Putty to login 192.168.99.100 docker/tcuser (Do not use the original windows Bash, it will cause problem when using $(pwd) in docker --volume parameter)
4. cd /c/Users/yourname/Document/jekyll_site
5. jekyll new .

docker run --rm --label=jekyll --volume=$(pwd):/srv/jekyll -it -p 0.0.0.0:4000:4000 jekyll/jekyll:pages jekyll new .

5. jekyll s --force_polling

6. Browse the page in host browser with http://192.168.99.100:4000

iperf client參數

iperf -c 192.168.1.31 -P 20 -i 1 -p 5001 -f m -t 99999

Validate PCIe's Speed and Width under Linux

1. use `lspci` to list all pci devices
The number less than 7f:xx:xx is for CPU0
more than 80:xx:xx is for CPU1

2. use 'lspci -vv" to check the detail of target device
check the "LnkStat:"
 Speed 2.5GT/s is gen1
 Speed    5GT/s is gen2
 Speed    8GT/s is gen3

Width is the PCIe lances

Reference:
https://en.wikipedia.org/wiki/PCI_Express