Tutorial 4 : Introduction to RAID

The world of 56k internet connections, 256MB of ram, 10GB hard drive, and floppy disk has died. The technology driven environment we live in today is always looking for the a way to out due our current solution.  Now a day ram can be bought in multiple gigabytes, and hard drives have reached terabyte level.  Throughout this blog post I will give a basic introduction for various different ways to save your data by using one of the RAID (Redundant Array of Inexpensive Disks).

RAID is storing your information in multiple disk drives but they are treated as one by the computer.  By spreading out the stored information, you will capacity, speed, and reliability in different ways.  In my post I will briefly give an introduction and describe the four most common RAIDs, RAID 1, RAID 0, RAID 5, & RAID 6.

RAID 1 - Mirroring

RAID 1 uses two disk drives and creates two identical copy the data, hence the name mirroring.  Everything that the computer stores RAID 1 will send the information to both hard drive A and hard drive B.  Consequently if for some reason one hard drive A fails, hard drive B will still have all your information safe.  Not only will your information still be safe but your computer does not slow down if a hard drive fails it will continue to run at full speed.  Even though you as the user will probably not notice the difference if a hard drive fails, it is important to have a hot spare disk.  After replacing the dead hard drive A with the hot spare, hard drive B will mirror all the information it has to hot spare and it will be back to normal.  The only con is that RAID 1 is pricey.

Attached diagram demonstrates how the Raid 0 distributes file 1, 2, & 3.  

RAID 0 - Striping
Raid 0 is used with two or more disk.  The more disk that are in use the faster it will run.  What RAID 0 does it distributes the data evenly between the disks in use, that it is why RAID 0 is also known as Striping.  By spreading out the information through different hard drives you gain a lot of speed.  This is ideal for simultaneously working on both read and write request.  Sadly all is not good, thou being the fastest it is also the least dependable.  If one hard drive fails the entire system will fail, crash, and all data will be lost.  It is known that RAID 0 is actually least dependable then just having a stock normal one hard drive you get from a thick client.

Attached diagram displays how RAID 0 spreads out its stored information

RAID 5
Raid 5 uses three or more hard drives and RAID 5 hardware to store information.  Information is stored in all disk excluding one.  For example lets say you are have three hard drives A, B, & C.  Hard drive A & B will be used to store information, while hard drive C will be doing something called parity.  Parity calculates and then stores information on the remaining unused drive.  But don't get int confused there is no certain parity drive.  For example same scenario we have the same three hard drives but now we want to store a new file.  Now hard drive A & C will be in use to store information, while hard drive B is calculating the parity.  By doing this your performance increase drastically, information is read faster, and write speed is common.  If a hard drive fails with RAID 5  no data will be lost.  The system will still be up and running, but unlike mirroring you will loose performance.  With RAID 5 you can substitute a dead disk with the hot spare that I discussed earlier.  After the process of reconstruction the data on the new disk performance will be back to normal.  RAID 5 is commonly found in network servers everywhere.

Attached diagram displays how RAID 5 creates its parity code to save data

RAID 6
RAID 6 extends RAID 5 by adding an additional parity block.  So if you have four disk drives in use when it comes to storing information only two will actually store information, while the other two are calculating the parity.  The reason why this is used is because it protects against read failures during rebuild of a large hard disk which will usually result in loss of massive amount of data.  Performance wise it runs like RAID 5 it reads fast but writes slow and also needs hard ware to support it.

(There is no diagram for RAID 6, due to the similarities that it has with RAID 5)


Just like everything else when it comes to choosing which RAID is right for you, you must due an analysis and see what your trying to get out of the RAID.  For the normal PC user I strongly recommend for you to USE RAID 1.




REFERENCES:
http://en.wikipedia.org/wiki/Raid_0#RAID_0
http://www.ehow.com/facts_5148033_computer-raid.html
All photos have been made in Microsoft Paint, and created by Dario Gonzalez II

Secure Email Blog

Site:
http://www.guardian.co.uk/technology/2011/apr/04/epsilon-email-hack

Summary:

Epsilon, which handles email processing for major companies including banks and retail chains have been hacked.  Epsilon's service include JP Morgan, Chase, capital one, etc.  The computer hackers stole email addresses and names of millions of people.  Other information, such as credit card details, personal information such as phone number and address is said to have not been breach.  Banks have warned customer to expect fraudulent emails and to not reply also, epsilon has placed a warning on there web page noting that information has been exposed to unauthorized entry.  Also TiVo wrote to its customers saying "Please note, it is possible you may receive spam email messages as a result. We want to urge you to be cautious when opening links or attachments from unknown third parties."

Avatar

This is me WITH HAIR! (I have very short hair)

I had fun creating my avatar.  I tried to use the simpsonizeme.com but the site was always down, so I used tizme.com.  Throughout the creation of my avatar I tried a bunch a funky stuff like adding hats even a margarita glass.  But at the end of the day I tried to go for the Spanish soap opera look.  I enjoyed the customization the site offered, overall I believe this was a fun extra credit opportunity.

Database Project

Prior to working on this project I have never heard of Microsoft Access.  Everything was a learning experience for me.  I was so clueless that i did not know how to create a blank datasheet.  First of all, I learned how to import data through Access.  Also I have learned a number of functions in Microsoft Access such as how to edit a search criteria and make a certain field "read only".  Finally how to create and edit a query, form, and report.  I learned how to use the various types of different views. 

There are a few ways to make the functionality of the database better.  First of having a recently left query, why do not we just have a "left query" for no longer members.  I do not find any reason why we would want to have a query on recent customers that left.  Another adjustment I would is on the new members form, I add a new field "referred by," and give members who refer X amount of  members some type reward. 

Tutorial Blog 3: Different type of internet connections

We live in a very fast pace environment now a days in which we depend more and more on technology.  It has come to the point where virtually anything  from going to classes, paying bills, watching movies, and even keeping in touch with family and friends can be done online.  In my blog I am going to explain the different types of home (there are other types of business connections such as T1 & T3 but those are usually for businesses so I will not be discussing them) internet connections, and  their pros and cons to see which one can benefit you the most. 

1. Analog
In an Analog connection (AKA Dial up) the computer is connected to a modem that dials a phone number which is provided by your ISP (Internet service provider) in order to access the internet.  It is called an analog connection because you access the internet over a dial up signal.

Pros: Very Cheap, Can be used by multiple computers

Cons: SLOW (56k connection), pretty much obsolete in today's age, ties up the phone line, and internet can drop frequently.

Diagram on how an analog connection works

2. Digital Subscriber Line
Digital subscriber line aka DSL is the leading alternative to a analog connection.  Like an analog connection DSL uses a telephone line (2 wire copper telephone line) to connect to the internet but you do not have to use a modem to connect because it is always on and it does not tie up the phone line. 


Pros:  Always on, faster than analog, and does not tie up phone line
Cons: DSL connections work better when you are closer to your server provider.  If you live far away from your server provider you will not be getting what you pay for in terms of internet speed.  Also, you get a decent download rate, but your upload rate lacks severely.  Finally, DSL is not offered everywhere. They are only offered by your location if you live in the country. It is likely to say that DSL will not be provided to you.

Diagram on how DSL works

3. Cable
Accessing the internet through a broadband connection can be done by use of a cable modem.Cable internet connection is a step above a DSL connection.  Like DSL, it is always on but instead of using a telephone line to connect to the interent it uses a TV line.  Cable Internet works by using TV channel space for data transmission with certain channels used for downstream transmission, and other channels for upstream transmission.  The way it works is that you will use a co axle cable to connect the cable modem to the cable input in your wall.  You can either connect your desktop to the cable modem or buy a router to enable wireless internet that will allow you to connect multiple devices to the internet connection.  I personally use a cable connection and I love it.


Pros:  Faster than DSL and Dialup, Does not tie up the phone line, Support heavy data movement such as streaming movies or online gaming, and it is always on.


Cons: Slow connection through online peak hours, initial connection fees can be high, like DSL cable is not available in all areas

 

 

 

 

 

 

 

Diagram on how Cable connection works

4. Wireless Internet
Wireless internet is one of the newest internet connections that have been introduced to the market.  Instead of using a telephone line or TV line to connect to the internet, wireless connections connect through radio frequency band.  This is still fairly new technology and difficult to find a provider for it.


Pros:  Completely wireless, always on, does not tie up the phone line, can be used by multiple devices
Cons: Hard to find a service provider, new technology, and expensive


(no diagram for this type of connection)




I hope my blog helped you in your process in choosing which type of internet connection to choose.


References


http://www.webopedia.com/quick_ref/internet_connection_types.asp
http://www.computertroublesolver.com/
http://www.superpages.com/supertips/cable-internet.html
http://www.wikipedia.org

(Picture made in paint by Dario Gonzalez, excluding cable connection which is found on computertroublesovler.com)

Web 2.0 Project

Self Critique

I felt the presentation was consistent with the theme. It began by indicating there is a organization that was not an earthquake relief program, which is what usually comes to mind when one thinks of donating money to Haiti. The description was sequential in that sense that I spoke about HCS, its beginning and what they do to help communities in distress.

I believe that I made valid claims and answered most if not all question before the audience had the ability to ask.  I started the presentation with a question to grab the audiences attention.  I believed that I avoided clutter by only showing simple text and by displaying one if not two pictures most per slide.   My only downfall is that I had a few slip ups while narrating the slides by stuttering.

What I Learned

First of all I have become an expert on the non profit organization of HCS.  Also I have learned many new web 2.0 features, prior to this project i have never made a video.  I had to find a screen capture program, manipulate the settings to perfection, and finally upload it on youtube.  In fact I spent a lot of my time trying to figure out how to operate the screen capture program (CamStudio).  Overall I believe the project was a great learning experiance, and it has motivated me to make my own personal tutorial videos and upload them on youtube.

Tutorial 2: Choosing the proper layout for your presentation

Have you ever sat through a dreadful presentation  where it seems that you are looking more at the clock then the presenter?  I know I have, and I thought to myself, I would hate to be that person boring everyone to sleep.  Usually a bad presentation starts off with a poor layout.  I decided to create a tutorial for everyone on the proper way to create a Microsoft Power Point layout for your presentation.

Getting Started


There are two ways to start the process of choosing the layout of your presentation.  You can either go for a custom layout that you can create, or use a layout that you can download via internet.  Lets start off from and create our own layout instead of just downloading one.  The first thing you need to do is choose the style of your slides. You do this easily by hitting design on the ribbon tab and choosing the slide to your preference.

Attached:  Choosing the Layout of you Microsoft Power Point slide.

After choosing a style now you can edit it to your liking.  You can change everything about it from the color to the texture.  What you want to do is click on background style.  You can choose new colors in the background style windows.  If you cannot find a color that you want to use try using kuler.com, they will give you the numerical value for each color.  Once you have picked a color you like, simply copy the number and place it into power point.  If you want to do further modifications to your template click on format background and edit to your preference.

Attached:  Formatting backgrounds in Microsoft Power Point.

Maybe creating a template really is not your thing.  There are plenty of sources to download Power Point layouts.  You can find them by just entering "Power Point Templates" in any search engine.  But here are a few links:

Powered Templates

Power Point Styles

Once you have found a layout that you want to use simply download it, uncompressed the file and open it with Microsoft power point.  The power point template that you have downloaded might come with its own text, just simply delete it and add you own.  This is completely legal if you download from the proper sites. Here is a picture just in case there is any confusion.

That is it.  Pretty simple, I thought so too.  As my business computing professor once stated, "design is more than how something looks" and "presentation design is about finding solutions for sharing ideas." You always want to make sure you do this in an interesting manner to capture and maintain the audience's attention. You need your design to be completely error free.  When I say error free I am referring to graphics and of course your facts.  Choose a design to your preference and that is easy on the eyes.  I personally prefer a dark background with light lettering.  Make your presentation easy to read by using big letters and clear font. No one wants to squint their eyes.  Also, be clear and obsess about your ideas, not the tools used in performing the ideas, but about the message you are trying to send to your audience.  Do not stress empty space, empty space is ten times better than clutter.  A professor at MIT once said "Simplicity is about subtracting the obvious and adding the meaningful."

Here are a few common mistakes when using images in you presentation.  Always try to avoid the following

• Small images
• Random images
• Image use that looks accidental
• Pix-elated images
• Watermarked or copyrighted images
• Disorted Images
• Clip Art
• Cliche images
• More than 1 image per slide.

Attached:  Is a power point slide of my two dogs Chico (right) and Nina (left).  Can you see whats wrong with it?  The text to the right is to SMALL!!!  This is something that you should try to avoid.

 

 

 

 

 

 

 

 

Attached:  Is another power point slide of my two dogs and roommate Jeff.  Can you see whats wrong with this?  The clutter makes it look disorganized, you dont know were to begin.  This is something else you should avoid.

 

 

                       

Always remember that the first 30-60 seconds of your presentation should be directed to catching your audience's attention  and one of the easiest ways to catch your audience attention is by using visual aid.  What could be better visual aid then a well thought out power point slide?  Take everything I talked about to consideration when choosing your design and you are guaranteed to do well.