Operating Systems – Week 6 Assignment
I/O Performance Analysis
Start your Linux Partition from a fresh boot and open the Terminal. Do not open any other applications at this time.
NOTE: You may need to install the “sysstat” and “iotop” package for this exercise:
apt-get install sysstat
apt-get install iotop
run the following command to create a 50MB test file
dd if=/dev/zero of=test.file bs=1024 count=50000
Now run this command to repeatedly create another file from the first file. This is creating I/O load on the system.
while true; do dd if=/test.file of=test2.file bs=1024;rm test2.file; done
Using iostat watch the I/O for your devices and all of its partitions over 30 second intervals. List the command used and record your findings. Do not display CPU statistics.
Using iotop, report which three processes are the most I/O intensive.
Add 3 new 50 MB Fixed Size Virtual Disks to your linux Partition. This is done using the Virtual Box interface while your Linux Virtual Machine is shut down.
Switch to the root user
sudo su –
Using fdisk create 3 new “linux raid auto” partitions. One for each new drive added. Use the full space available on each disk.
i.e. /dev/sdb1 /dev/sdc1 /dev/sdd1
install “mdadm” package
apt-get install mdadm
*If asked for a “mail server” choose “No Configuration”
**This can take a few minutes to install.
Create a striped array (RAID 0) using all three disks.
Create Filesystem on New Raid 0 Array
Mount your new striped filesystem
What is the size of the filesystem? Why?
Repeat Part 1 of this assignment but this time make sure you are using your new striped filesystem. To do that just change to that directory
Summarize your findings about your new RAID 0 filesystem and iostat output.
Did you achieve desired results? If not, why not and what would need to be changed in a real world production server to achieve desired results?
You will submit a Word or Libre Writer Document which contains results from the above analysis and responses. I do not have access to your system so you need to be sure to provide screenshots for anything I cannot possibly know.
I don’t need screenshots for every piece of output you analyze during this assignment. Just give screenshots which show snapshot information to support your overall findings.
Please insert your screenshots into your word document with supporting documentation which meets all requirements. You will be penalized for any results which are not backed by proof.
A large portion of this class is exploring and researching solutions on your own! You will continue to operate as a systems administrator / analyst and thus you will be expected to figure out what you need to know on your own.
You will not find exact solutions in your book which give you what you need to know to complete this assignment or future assignments. What you will find in your book is an in depth analysis of how an operating system manages devices at a low level. This is imperative in understanding what the resulting data values mean from your assignment.