SSH-Daemon

H5

I did this exercise with:

HP Pavilion 15-aw022no

AMD A9-9410 (2.9GHz, 2 Cores)

8GB DDR4-SDRAM 2133MHz (2 x 4)

256GB SSD

AMD Radeon R7 M440 (2GB, GDDR3)

Ubuntu 17.10 (Live USB)

Instructions for exercises from: http://terokarvinen.com/2017/aikataulu

 a) Install SSH-daemon

Command: sudo apt-get update && sudo apt-get install ssh -y

b)Protect your PC with firewall but make a hole for SSH first.

Command for SSH hole: sudo ufw allow 22/tcp

Command for setting up the firewall: sudo ufw enable

When working with remote computers with SSH, remember to allow SSH first so you do not lock yourself out.

c) Transfer files on SSH

I made a text file called a.txt for this exercise to /home/matias folder. With command
scp -r /home/xubuntu/a.txt matias@174.138.6.58:/home/matias/  I copied the file to my VPS. Just needed to confirm fingerprint with yes and give password to VPS.

100% of 26 bytes transfered with speed 0.6kb/s and in 00:00 time. Success.

d) Automate login with public key method

I found very comprehensive instructions from: https://www.ssh.com.

First I created SSH key pair on my local PC for user authentication with command ssh-keygen. This generates public and private keys with rsa algorithm. Next I needed to choose file in which to save the key, I chose the default folder and file. Lastly I gave a passphrase for encrypting the key. Image below is from SSH’s homepage, and it’s demonstrating the key creating process.

virtual.png

Once key is created, I needed to copy it to a server. I used my VPS. On my local PC I gave command ssh-copy-id -i /home/xubuntu/.ssh/id_rsa.pub matias@174.138.6.58. This command copies id_rsa.pub file which is where the key is from path /home/xubuntu/.ssh to my virtual private server user matias in address 174.138.6.58.

To test if this is successfully accomplished I logged to my server via SSH      ssh matias@174.138.6.58. Now it asked passphrase which I created earlier.

Screenshot_2018-02-25_01-20-07

I typed it and clicked Unlock. I successfully logged in to my VPS.

keygen.png

j) Install, configure and start Sysstat. Investigate load history and analyze the results.

24.2.2018

23:27

This is done on virtual private server (Ubuntu 16.04)

Installed Sysstat with command sudo apt-get install sysstat -y. Then I edited sysstat configuration with command sudoedit /etc/default/sysstat from ENABLE=”false” to ENABLE=”true”.

Screenshot_2018-02-24_21-42-39.png

Then I launched it with command sudo systemctl start sysstat and checked that it is functioning with command sar.

Screenshot_2018-02-24_21-47-35.png

Now Sysstat is demonstrably started. I will come back to this later, when there’s something to analyze.

 27.2.2018

 23:34

Following results with command iostat.

iostat.png

Linux 4.4.0-112-generic = System’s kernel version

(kurkku) = Computer’s hostname

02/27/18 = Date when the data was collected

_x86_64_ = Architecture of the system

(1 CPU) = How many CPUs available on system

%user 0.15 = User’s application level utilization of CPU in percentage

%nice 0.01 = User level with nice priority utilization of CPU in percentage

%system 0.11 = System’s kernel level utilization of CPU in percentage

%iowait 0.02 = Time when CPU is waiting an outstanding disk I/O request in percentage

%steal 0.08 = Involuntary time virtual CPU is waiting the hypervisor is servicing another virtual processor in percentage

%idle 99.63 = Time CPU is idling in percentage

Device = This column gives the device name as listed in the /dev directory

tps 0.57 = Number of transfers per second that were issued to the device

kB_read/s 0.51 = Amount of data read from the device in kilobytes per second

kB_wrtn/s 7.56 = Amount of data written from the device in kilobytes per second

kB_read 943486 = Total number of kilobytes read

kB_wrtn 14001209 = Total number of kilobytes written

I think we can draw a conclusion that CPU is in not in hard usage.

Sources for explanations:
https://www.thegeekstuff.com
https://www.computerhope.com

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