ssh 登录的提示界面定制

ssh 登录欢迎界面如下：
Welcome to Ubuntu 14.04.1 LTS (GNU/Linux 3.13.0-37-generic x86_64)

* Documentation:  https://help.ubuntu.com/

  System information as of Fri Dec  4 19:27:24 CST 2015

  System load:  11.38               Processes:          435
  Usage of /:   76.3% of 517.82GB   Users logged in:    1
  Memory usage: 8%                  IP address for em1: 192.*.*.*
  Swap usage:   1%

  => /mnt/storage is using 89.6% of 1.79TB

  Graph this data and manage this system at:
    https://landscape.canonical.com/

Last login: Fri Dec  4 19:27:24 2015 from 192.*.*.*

------------------------------------------按下面操作就行---------------------------------------------------------------
$ cd /etc/update-motd.d/
$ls   # 00-header也可以改
00-header     50-landscape-sysinfo  91-release-upgrade  98-reboot-required
10-help-text  90-updates-available  98-fsck-at-reboot
$ vim 50-landscape-sysinfo
加入 这句  /usr/bin/landscape-sysinfo
就会显示如下信息;
  System load:  17.47               Processes:          392
  Usage of /:   76.3% of 517.82GB   Users logged in:    1
  Memory usage: 9%                  IP address for em1: 192.*.*.*
  Swap usage:   1%

  => /mnt/storage is using 89.7% of 1.79TB

  Graph this data and manage this system at:
    https://landscape.canonical.com/
---------------这样就可以，在登录时就能知道系统的大概情况了------------------------------------