Virtualization

It has been quite a while since I last wrote a post- my work schedule is pretty crazy, and I was often falling asleep as soon as my head hit the pillow. I'm planning on my next article, but until then, here is a great entry on Virtualization from my brother Michael. He is incredibly smart and knowledgeable about computers- you could call him the expert networker! Here we go:

Virtualization (or When you ride alone, you ride with your local utility company! DUN DUN DUNNNNNNN)

Greetings readers, I am the Not-quite-so-novice Networker, you can just call me Mike. I am Caitlin's favorite younger brother (or not, I dunno she may be telling everyone she knows that I suck more than a Electrolux or somethin'). Anyway I am here to introduce in a interesting manner technologies, issues, and software that you will eventually need to get familiar with should you actually like all this computer fixing and head down the dark path full of headache, silliness, and (justified) paranoia and get a full time IT job. The key words here being "interesting" (I'm allergic to writing boring articles, just thinking about it makes me sneeze) and "introduce" (You know what else I'm allergic to? Besides Rocky Mountain Cedar and cats? Writing long complicated articles, I'll crack open the door for you, you'll have to enter it yourself, I'll provide some handy links for you so that you can learn more though).Anyway let’s get started.

Let me start with a topic that is close to my heart, and when I mean close to my heart, I mean I have been frantically studying ever since my company committed tens of thousands of dollars towards and expects me to maintain and fix (That’s one thing Entry-Level  IT workers need to have, the ability to hit the ground running on most new technologies on little notice, training is for old, important people) and that is Virtualization. So what is Virtualization you ask, well let’s start with how things generally are now.

If you follow best practices (and you should), you generally have one server for each application your network provides, whether that be providing mail to your users or web sites or file storage, it doesn’t matter if you have several servers doing the exact application (for redundancy) or having multiple servers working together on one application (which is clustering), so long as that server is doing just that application (doing otherwise would make problem much more serious as they’ll effect more than one application). However nowadays servers are pretty powerful (and expensive) and simply having them do just one thing is a waste of energy and money. So what do we do? We virtualize, that’s what!

Virtualization takes a server’s software, separates it from the hardware that it connects to, and turns it into a mobile package called a virtual machine, which can be transferred between servers, restarted, duplicated, among other things at will. A powerful server running what is called a hypervisor can run several of these virtual machines at once, splitting the server’s resources efficiently between all of them. You can consider it similar to the concept of carpooling, having 4 people drive 4 cars to 4 destinations is a waste of gas and money, having 4 people drive in one car to their destinations is far more efficient. Only in this case, should the car decide to spontaneously explode, all of the passengers can hop into the car next to them going at the same speed and continue on without a single delay.

Wanna know more about this technology? (You should!) Then check out these links:

VMware: www.vmware.com , the leader in Virtualization at the moment, their website provides all sorts of information on virtualization, as well as free software so you can give this virtualization stuff a try yourself!

Microsoft: www.microsoft.com/virtualization/en/us/default.aspx , Microsoft also is in the virtualization business, however their Hyper-V isn’t as popular as VMware’s vSphere. Still worth a look, though.

Wikipedia: http://en.wikipedia.org/wiki/Virtualization , Good place to go to learn about all the various things virtualization is used for.

PATA vs. SATA

Computer components and devices are so heavily intertwined that it is hard to separate entries into very basic topics so that beginners can understand what I am talking about. I consider this entry 3 of 3 of what was initially just going to be one entry- HDD vs. SSD. That didn’t work out so well, but at least it gives me more stuff to write about.

This entry is about computer component interfaces. When I was first starting to learn about the inside of computers, this section took me a while to understand  but all it is just how computers components connect to one another and how information travels to each component. There are different types of interfaces that were used more in the past (SCSI, Firewire, Centronics), but the two I will be focusing on are PATA and SATA.

Though it is not as popular as it once was, expect to work with PATA on older computers. PATA stands for Parallel AT Attachment, and is the name given retroactively to devices that transmit data over parallel (Wikipedia, 2011). It is just easier to assign the one name, because PATA has been called by different names over the years (IDE is the most common, but EIDE, ATA, ATAPI exist out there too. It’s all PATA now). PATA transmits data 8 bits over 8 transmittal wires (one bit per wire= 1 byte) through a 40 pin ribbon cable that can connect up to two drives inside the computer.

SATA stands for Serial Advanced Technology Attachment, and this bus interface is an improvement on PATA in many different ways. Unlike PATA, SATA can only connect to one drive, but in return it provides higher data transfer, reduced bulk (those ribbon cables are huge!), and it’s hot swappable! An example of a common use of SATA transfer is the USB flash drives that are like a mini portable hard drive. I remember those little devices becoming popular when I was in college; a godsend since I didn’t have to carry floppy disks or those giant Iomega disks around with me anymore. SATA transmits data one bit a time in a single stream. The PATA interfaces can transmit data at speeds between 5 MB per second to 133 MB per second; SATA transmits much faster, at rates between 150 MB per second to 300 MB per second (Blogulate, 2007).

So why does SATA transmit data faster than PATA? This took me a while to understand because one would think that with 8 bits going over a wire at once, that would mean information would be sending faster than in one single stream. Here are the reasons why this isn’t the case:

1.      Those 8 bits traveling the wires may not reach the destination all at once. The computer will start to slow down when it has to wait for all those bits to catch up (Blogulate, 2007).

2.       The more wires (This vs. this) there are, the higher the chance there is for disturbances (Blogulate, 2007).

3.       Those 8 bits have to convert back into one stream in order for the destination port to read them, and this adds time. Since serial is already being transmitted in one single stream, no conversion needs to happen, and time is saved (Wikipedia, 2011).

PATA and SATA are not interchangeable, so any devices will have to be one or the other, unless there is an adapter.

Blogulate. (2007, December 2). Why is Serial communication preferred over Parallel ? Retrieved June 8, 2011, from Blogulate: http://blogulate.com/content/why-is-serial-communication-preferred-over-parallel/

Wikipedia. (2011, May 31). Parallel ATA. Retrieved June 9, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Parallel_ATA

Wikipedia. (2011, June 4). Serial ATA. Retrieved June 9, 2011, from Wikipedia: http://en.wikipedia.org/wiki/SATA

Solid State Drives

The hot computer component in the news is the solid state disk drive (SSD), named for having no moving parts of the inside of its unit, unlike the fragile hard disk drive (HDD).  An example of a solid state storage device is the memory card put into a digital camera. That technology is becoming another option to use as a storage device for computers instead of a HDD.  SSDs have their advantages and disadvantages compared to HDD, and while it is popular, they may not be replacing HDDs completely any time soon.

There are many reasons why people (like me) advocate making backups of a hard drive; the biggest is because hard drives can and do fail. The hard drive is like the cerebral cortex:  it is where the memory is located. (Wikipedia, 2011). A monitor or a motherboard can be replaced without losing information, but once the hard drive is dead, hours of work, time, and money are gone in an instant. With the advent of mobile technology, it is more important than ever to have a storage device that is stable and can handle a few hard knocks. The SSD is becoming a legitimate hard drive alternative for mobile devices where a traditional hard drive would be damaged by the constant moving- and possibly dropping- of said devices.  

While HDDs have platters with a read/write head reading the tracks on the heads (read the previous entry to get a lowdown on all those parts) there are no moving parts on an SSD and it stores memory electronically (Tyson, 2011).This is also called Flash memory. There are many perks to using SSD over HDD besides its sturdiness: it weighs less, starts up faster than HDD, and magnets have no effect on it (Wikipedia, 2011). However, HDD disk drives will not be obsolete anytime soon, as even though prices are dropping, SSD is still more expensive than HDD, and the storage sizes for it aren’t anywhere near as large. This chart on Wikipedia gives a good outline on the other differences between SSD and HDD.

There is also the perception that SSDs aren’t as reliable as HDDs. In a study mentioned in this article, SSDs were returned to stores as malfunctioning at a higher rate than HDDs. Now, this article was written in December 2010, and as I am writing this entry in early June 2011, this is an eon of time for technology.  In another article from March 2011, Seagate is promoting their business line of SSDs which should be incredibly powerful and reliable and also incredibly expensive. This should give an idea on how fast technology is improved and updated: one article is about how SSDs are being returned at a high rate as malfunctioning, and another article from the same website a few months later is about how much SSDs have improved. Who knows what will happen in a year from now? Oo, now I have a blog article to write about…in a year from now.

One last thing I have to talk about is TRIM. It’s something that is mentioned a lot during SSD discussions so it’s important to know what it is. When information is deleted from a SSD, the hard drive won’t delete the singular file right away- it only deletes information in blocks. After time, the SSD slows down because it is full of files marked for deletion, arranged in the blocks. Once the blocks are full, then the SSD will start deleting the blocks, which takes a long time. However, if both the operating system and the SSD have TRIM support (and both of them need to support TRIM for this to work) then the files marked for deletion will be deleted at that time, not when the blocks of deleted items are full.(Hilton) Just think of it as the end user taking control of their hard drive.

Hilton, J. (n.d.). What is TRIM support? Retrieved June 6, 2011, from Top Ten Reviews: http://solid-state-drive-review.toptenreviews.com/what-is-trim-support.html

Tyson, J. (2011). How Flash Memory Works. Retrieved June 6, 2011, from How Stuff Works: http://electronics.howstuffworks.com/flash-memory.htm

Wikipedia. (2011, April 25). Cerebral Cortex. Retrieved June 6, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Cerebral_cortex

Wikipedia. (2011, June 4). Solid State Drive. Retrieved June 6, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Solid-state_drive

Hard Disk Drives

I like to buy external hard disk drives like I do nail polish: I just like to pick one up when I’m walking around Target aimlessly.  I’ll remind myself that I haven’t bought any for several months, and heck, I’ve been good, and I deserve it. However, unlike the nail polishes, where I find them underneath Wii games and magazines, I never forget to use my external hard drive. Like I mentioned in previous entries, a fear of losing my awesome music collection can keep me up at night, so I back up again and again, on different hard disk drives (HDD) besides the one inside my computer.

A hard disk drive is either an internal or external computer component that holds data (Wikipedia, 2011).A hard drive on a personal computer is the opposite of cloud computing: as data is on one computer, and if the disk drive fails, then that data is gone for good. Hence, create backups! Since the HDD is a fragile piece of equipment with moving parts inside of it, it is best for a desktop. It can be used in laptops, but it is not recommended since laptops can be dropped and knocked around easily. (Trust me on this- I don’t know how my laptop survived ten years with me)

The reason that HDD are so delicate is that the components inside them are sensitive. If a hard drive is opened (which shouldn’t be done unless it is defective) it looks like a little record player with several parts:

Platters- The discs inside the HDD. Each side of the platter is called a head (Torres, 2005).

Tracks- These are like grooves on a record - circular paths written on either side of the platter (Torres, 2005).

Sectors- Smaller portions of a track, which contain 512 bytes of data (Torres, 2005).

Cylinders- The number of tracks on each side of the platter. These cylinders run straight down the set of platters, so that it forms a cylinder. (Partition Manager Software, 2011)

When buying a new hard drive to be used, especially the main internal hard drive where main data storage will be, it’s important to partition and format the hard drive.

Partitioning is done first- its separating the hard drive into different section so there can be more than one operating system on it. (Tip: If installing both a Microsoft O/S and a Linux O/S on the same drive, install Microsoft first).  Partitions are considered logical drives, and they are listed on computers by a letter.  On a Windows based system, the main logical drive is the C drive (Docter, Dulaney, & Skandier, 2007). 

Partitioning assigns placement on a hard drive; formatting allows the partition to store data in a certain way.  Older (like, DOS old) formatting versions for Windows based system are FAT16 and FAT32.  Formatting should be done with the newest format version, NTFS.  All versions allow for a file allocation table and a root directory. When saving files, this is where they are saved as its name, followed by a period and the extension (ex: name.docx).  NTFS is backwards compatible with the FAT systems, but expands on it by allowing files to be compressed and file level encryption, among other features. (Docter, Dulaney, & Skandier, 2007)

Next time I’ll talk about the hot new internal storage device thats all up in the news: the solid state hard drive.

Docter, Q., Dulaney, E., & Skandier, T. (2007). CompTia A+ Complete. Indianapolis, Indiana: Wiley Publishing, Inc .

Partition Manager Software. (2011). What is disk formatting? Retrieved June 3, 2011, from Partition Manager Software: http://www.partition-magic-manager.com/partition-magic/partition-magic-help/WhatIsDiskFormatting.php

Torres, G. (2005, August 4). Anatomy of a Hard Disk Drive. Retrieved June 3, 2011, from Hardware Secrets: http://www.partition-magic-manager.com/partition-magic/partition-magic-help/WhatIsDiskFormatting.php

Wikipedia. (2011, June 2). Hard Disk Drive. Retrieved June 3, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Hard_disk_drive

Tech IPOs- Past and Present

I have a LinkedIn account. It is a professional version of Facebook where you can list a resume, give and receive recommendations to colleagues, join groups, and it is often the first place that companies and recruiters go to view potential new employees. LinkedIn has garnered a lot of attention in the news recently for its initial public offering- commonly referred to as an IPO- and there are concerns that its arrival to public trading is will bring back memories of the Dot.com burst that happened in the early 2000s.

 It isn’t just LinkedIn that is incredibly popular with investors right now- many technical startups including Groupon, Zynga, and Facebook are currently considering whether to offer their own IPOs, and underwriters are willing to do business with them.  Investment bankers are on the lookout for the next big innovative tech company to issue an IPO with, and excitement is high for these types of social networking websites (Tam, 2011).

In my research for this entry, there is some similarity between the rise of the Dot.coms and the rise of social media in terms of sheer popularity and willingness of banks willing to invest in these companies. In the early nineties, if a company wanted to become more popular, they just added an “e” to the front of their product or name. In 2000, seventeen different Dot.coms had commercials during the Super bowl (Timelines, 2011). Now most of these companies are in the history books for their spectacular crash and burn.  This link from Timeline gives a fascinating timeline of when the first Dot.coms started arriving until the bubble burst and the aftermath of it all. Today social media networking websites such as Facebook has become a central hub for people to communicate and plan events with.  500 million people have Facebook accounts, which I imagine is more than the number people who had Geocities webpages (oh, how I miss my page I created in 1996).

This brings up two issues that I’m going to address: what an IPO is and if there is a difference between the startup of today compared to the ones of ten years ago.

For companies past and present that wanted into the stock market, they have get funding by raising money through an underwriter from an investment bank. Goldman Sachs and Morgan Stanley are two examples of underwriters.  These underwriters drum up interest in the company by going to large scale investors to finance the startup so enough money is raised to issue stock. Once the underwriters figure out who will invest, the market conditions, and any other important information, the startup and underwriter determine the initial stock price (Investopedia, 2011). This entry from Investopedia gives an in-depth look at the process of issuing an IPO.

This process has been around for a long time but the term “IPO” didn’t come into the public lexicon until Dot.coms were planning and issuing their IPOs. The novelty and popularity of these companies caused a lot of people in charge- underwriters, the creators of the Dot.coms, investors- to overlook bad business plans (Wikipedia, 2011). There were startups of this era that became successful – Amazon and Google- but these were the exception because they had good business plans that accounted for the fact they wouldn’t have revenue profit (edited 6-2-11)for the first several years of business.  The rest of the companies blew through millions of dollars in months and went bankrupt (Wikipedia, 2011).

So now that LinkedIn has had their IPO, it “closed at $94.25, more than 109% above the $45 IPO price” (Baldwin & Selyukh, 2011),interest in underwriting is incredibly high for other social media sites and people are understandably worried that companies will be overvalued, and history will repeat itself with money and jobs lost to bad planning (Noguchi, 2011).

Fortunately, there are some positive differences between the internet startups of today- LinkedIn has been around for eight years and unlike the ones of ten years ago, does not have to spend millions to attract users because they already have them. Technology has also made strides in the decade- hardware is cheaper and faster than it has ever been. Ten years ago computers users were using the incredibly slow dial up to access the internet- now those users are a minority since most people are using cable modems and DSL lines (Noguchi, 2011).

While it is good to be cautious, especially when it comes to hundreds of jobs and millions of dollars, it seems that some hard lessons have been learned and people are excited to invest in innovative tech startups again. 

Baldwin, C., & Selyukh, A. (2011, May 19). LinkedIn share price more than doubles in NYSE debut. Retrieved June 1, 2011, from Reuters: http://www.reuters.com/article/2011/05/19/us-linkedin-ipo-risks-idUSTRE74H0TL20110519

Investopedia. (2011). IPO Basics: Introduction. Retrieved June 1, 2011, from Investopedia: http://www.investopedia.com/university/ipo/default.asp

Noguchi, Y. (2011, May 26). In LinkedIn IPO, Hints Of Another Tech Bubble? Retrieved June 1, 2011, from NPR: http://www.npr.org/2011/05/26/136655334/in-linkedin-ipo-hints-of-another-tech-bubble

Tam, P.-W. (2011, May 31). Echoing Around Tech Confab: 'Call Me'. Retrieved June 1, 2011, from Wall Street Journal: http://online.wsj.com/article/SB10001424052702303654804576349482665455162.html?mod=WSJ_Tech_LEFTTopNews

Timelines. (2011). Dot-Com Bubble. Retrieved June 1, 2011, from Timelines: http://timelines.com/topics/dot-com-bubble

Wikipedia. (2011, May 30). Dot-com bubble. Retrieved June 1, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Dot.com_bust