Tutorial Blog 4: RAID & HSM

We recently were explained the differences between each RAID as well as the difference between thin and thick client computing as well as what Hierarchical Storage Management is.
I am very disappointed that this class is almost over because I have had such a great time learning about all the different types of computers and different software and hard drives that are available.

                                              Created By Shannon DuQuesnay, Copyright 2011

 

 

RAID 1 – Mirroring uses a pair of drives
each block of data is written to both drives
block – basic unit of data read/written to storage
single drive failure à no data is
lost, system still runs at full speed, replace failed drive and re-mirror
50% overhead – cost per GB is doubled
“Hot spare” disk – replaces dead disk drive

RAID 0 – Striping 2 or more drives
no extra copies-blocks of data spread across all drives
multiple disks simultaneously working on both read and write requests
the more disks, the faster RAID 0 works
no redundancy à single drive failure à entire RAID 0
fails, all data lost, crashes, replace drive, rebuild array, reinstall OS and
restore data
less reliable than single disk drive
cost per GB is unaffected

RAID 5 3 or more drives
data blocks spread across all drives except one
parity – calculated and then store on remaining drive – used to protect data
parity = 1 if sum of data bits is odd
parity = 0 if sum of data bits is even
fast reads, moderate write speed (must compute parity)
single drive failureà no data lost,
still running but reduced speed à replace failed drive and allow
system to reconstruct the data on the new drive before another failure
hot spare disk – replaces immediately
(N-1) drivers usable for data
common in network servers

RAID 6 any form of raid than can continue to execute in the presence of 2 concurrent
disk failures
capacity = (N-2) disks
fast reads, writes slower, needs hardware support
1TB+ disk

HSM: Hierarchical Storage Mgmtsome data used regularly
some data rarely touched
automated, rules-based system allows us to take rarely used from expensive
storage to cheap (unknown to user)
Benefits: expensive high speed storage used for small “working set” and rarely
used data stored to SATA disk or tape

Thin Client Computing

Thick clienthardware – standard Desktop PC
powerful CPU and Lots of RAM
NIC
storage: hard drive, optical, USB
IO: screen, keyboard, mouse, sounds
software: OS, utilities and applications

Thin Clienthardware – specialized device, very small
modest CPU and RAM
NIC
No Internal hard drive, might have optical or USB
IO: screen, keyboard, mouse , sound
like a terminal: processing and storage occur elsewhere

Created by Shannon DuQuesnay, Copyright2011

Actioncentralized CPU, RAM, Storage
use terminal server approach: server OS, terminal server application shares the
servers resources and installed applications among multiple users
application issues – licensing, different versions
virtualization: each user has own VM with OS and applications à standard, unmodified
OS and apps; more flexible, resources are pooled
VM features – deploy from templates, snapshots

Why Thin?more efficient use of HW resources
typical end user PC is underutilized: CPU idling, much unused RAM, vast unused
disk space
centralized CPU, RAM, storage more fully utilized
dynamic allocation of CPU and RAM to users as needed
allocate only necessary amount of storage
allocate resources in nonstandard increments
improved management/support
hardware upgrades: nonstandard increments, less inconvenience to user
centralized backup: data, entire machine (image backup, snapshot)
linked clones: rapid deployment, disk space savings, fast patching, software
updates, pooled computer (retain personality but still fresh daily)

encrypted email

In my ISM3004 class we were just taught how to acquire a personal e-mail certificate.  We were also taught step by step how to send a digitally signed and encrypted e-mail message.  We were first told to download Mozilla Thunderbird.  We set it up through our UFL webmail account.  Mozilla Thunderbird was very new and interesting.  It was fun to learn a new way to receive email that I did not even know existed before this class. 
I then downloaded and exported my certificate from VeriSign where I sent a digitally signed email to a professor and then received an email with the professor's public key which I used to send an encrypted email.

Here are both screen captures after I sent and received both emails from the professor

Sending encrypted emails is very important.  Below is a link explaining a situation where NASA failed to secure their Computer System Security.  It ended up endangering the space missions but could have been easily avoided with only a few simple steps.  This failure to secure their computer system could have jeopardized the lives of many innocent people.

http://www.eweek.com/c/a/Security/NASA-Failure-to-Secure-Computer-Systems-Endangers-Space-Missions-Audit-741515/

In this article Famida Rashid explains how the Office of the Inspector General found vulnerabilities on six servers.  These vulnerabilities were connected to the National Aeronautics Space Agency. This could have caused ineligibility to Space Shuttle, International Space Station and even Hubble Telescope missions.  People claimed they had taken in account for vulnerabilities such as the ones that happened however Inspector General Paul K. Martin states how NASA failed to have a security program finding these problems as soon as they arose.  NASA has known about this for over a year and has still failed to enforce this.

This is such a simple task that someone would have to perform to avoid all of these insecurities and vulnerabilities NASA has been faced with.

NASA was also not properly disposing hard drives which exposed sensitive data.  They were not taking the precautionary steps necessary when dealing with the important information and data that NASA sends and receives every day.  They did not properly verify sanitation procedures.

Creating an Avatar

This week in ISM3004 we were assigned to create an Avatar.  I have been putting of this project thinking it was quite difficult.  Surprisingly it was not and ended up being one of the most entertaining assignments.  We were given a couple different places to make our Avatar.  I tried out a couple of them and DoppelMe was my favorite.


It was very easy to create an Avatar on http://www.doppelme.com because they gave you step my step instructions.  You started off choosing the gender and then went on to choose the hair and eye color.  It did not stop there, you could choose from a variety of different clothing options and change the color of each article of clothing. I went on to choose the type of shoe as well as any accessories I wanted to add.  Here is the Avatar I created on DoppelMe