Overview
For many software developers, Amazon Web Services (AWS) and Ubuntu Linux are our world. The Ubuntu instances on AWS have exceptionally performance, have almost unbelievable reliability, and are surprisingly affordable. Establishing a server on an AWS EC2 Ubuntu instance can be a little intimidating at first to setup, configure, backup, and operate. As such, there are numerous Ubuntu Linux tips and short-cuts that one learns on this development journey. Here is my growing list:
Updates to Ubuntu
What if after accessing the AWS instance using SSH via terminal (as described in post AWS WordPress 1: Create EC2 Instance, the login result to the Ubuntu instance shows the following message about pending updates?
Welcome to Ubuntu 16.04.3 LTS (GNU/Linux 4.4.0-1041-aws x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/advantage
Get cloud support with Ubuntu Advantage Cloud Guest:
http://www.ubuntu.com/business/services/cloud
18 packages can be updated.
0 updates are security updates.
*** System restart required ***
Last login: Wed Dec 27 19:31:25 2017
To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.
Updating the Ubuntu Linux AWS instance involves a few simple commands:
Fetches the list of available updates:
sudo apt-get update
Installs the updates:
sudo apt-get dist-upgrade
Cleans up /var/cache/apt/archives:
sudo apt-get clean
Removes old kernels:
sudo apt autoremove
Reboots the EC2 instance:
sudo /sbin/reboot
Getting Information on Disk Storage and CPU Utilization
It is important to understand how much disk storage and memory is being use and how much CPU is being utilized. Here are two commands and their typical responses on an AWS EC2 ‘t2.micro‘ instance.
Provide a list of storage devices with usage information:
df -H
Filesystem Size Used Avail Use% Mounted on udev 512M 0 512M 0% /dev tmpfs 104M 3.2M 101M 4% /run /dev/xvda1 8.3G 1.3G 7.0G 16% / tmpfs 520M 0 520M 0% /dev/shm tmpfs 5.3M 0 5.3M 0% /run/lock tmpfs 520M 0 520M 0% /sys/fs/cgroup tmpfs 104M 0 104M 0% /run/user/1000
Provide memory usage and CPU utilization information:
top
top - 19:52:37 up 3 min, 1 user, load average: 0.02, 0.07, 0.03
Tasks: 108 total, 1 running, 107 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.0 us, 0.0 sy, 0.0 ni,100.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 1014644 total, 817484 free, 45944 used, 151216 buff/cache
KiB Swap: 0 total, 0 free, 0 used. 813248 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1 root 20 0 37756 5720 3896 S 0.0 0.6 0:02.38 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:00.01 ksoftirqd/0
4 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H
6 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kworker/u30:0
7 root 20 0 0 0 0 S 0.0 0.0 0:00.04 rcu_sched
8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
9 root rt 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
10 root rt 0 0 0 0 S 0.0 0.0 0:00.00 watchdog/0
11 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kdevtmpfs
12 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 netns
13 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 perf
14 root 20 0 0 0 0 S 0.0 0.0 0:00.00 xenwatch
15 root 20 0 0 0 0 S 0.0 0.0 0:00.00 xenbus
16 root 20 0 0 0 0 S 0.0 0.0 0:00.02 kworker/0:1
17 root 20 0 0 0 0 S 0.0 0.0 0:00.00 khungtaskd
18 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 writeback
19 root 25 5 0 0 0 S 0.0 0.0 0:00.00 ksmd
20 root 39 19 0 0 0 S 0.0 0.0 0:00.00 khugepaged
Other Tips
I will continue to add to this collection of AWS EC2 tips as I discover them!
