Introduction to RAID
[ Thanks to bryanjrichard for this link. ]
"One of the most common techniques to improve either data reliability or data performance (or both) is called RAID (Redundant Array of Inexpensive Disks). The concept was developed in 1977 by David Patterson, Garth Gibson, and Randy Katz as a way to use several inexpensive disks to create a single disk from the perspective of the OS while also achieving enhanced reliability or performance or both.
"Before anyone erupts and says that RAID does not stand for ?Redundant Array of Inexpensive Disks?, let me start by stating that was the original definition. Over time, the definition has become more commonly known as ?Redundant Array of Independent Disks? perhaps so the word ?inexpensive? isn?t associated with RAID controllers or disks. Personally I use the original definition but regardless, either definition means that the disks are independent of one another. Feel free to use either definition since it won?t change the content of this article. Now, back to our discussion of RAID."
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Behind the cloud Redux
Cloud computing is the hot buzz phrase. But as both Shawn powers and I have no new technology, or even a new implementation of new technology computing cloud is highlighted. But that doesn't mean that it is well understood, either by those who design or are the ones who yells it, then follow the yellow brick road (or the latest edition of PC week). As several anonymous (and not so anonymous) commentators have said, it is only hardware, some good data links and some intelligent coding much more to cloud computing.
Because cloud computing means different things to different people (and at different times of the day), we must be on our terms and conditions clearly. Our friends at Wikipedia define cloud computing as:
Cloud computing Internet-based computing, with shared servers provide resources, software and data to computers and other devices on demand...
This definition works well enough for me, so let us examine it a little deeper. By definition everything Internet based tends not to have associated with a physical or geographical location. For example, when I go the Linux Journal website, I'm not thinking about, Houston, Texas, where the magazine officially. In fact, because actually Houston I think a few of us life, at the Linux Journal page as not everywhere. This is further underlined by the variety of comments from around the world to our musings.
Also, if you are a Googlesuche, an example of cloud computing, you are more likely to the beat to one server cluster is (IP-based), data center than locally on your physical location when they are, will occur to your servers in California (and I assume server in a data center in California you). Two examples - search yields and generic Web sites talking - pretty harmless data. It does not really where the servers are located, and there are no large crushing legal issues in reference to.
But if, for example, the Federal Government (we use the US one since that's where I am, but any Federal Government has the same set of questions) or more importantly, your company, decide, is it on cloud computing, then you can go as IT professionals we must not only part of the process, but we need questions, the tough questions at the beginning, not the day before the switch is thrown.
Cloud computing matters location. And also property. Lawyers must be included. And much careful planning. Here are some things to note: who owns the cloud, you're going to use? Are contracting with a third party for storage or build it from scratch. If local law enforcement show up with an application, the sophisticated data pass, who is responsible for turning this data? When? Under the laws of the State (or country)? Who owns the data paths? Is traffic shaping? How does it all nodes in the cloud? If you work for an international company, response is to say Singapore? Answer it in Virginia or the United Kingdom identical his target? Who is he that is responsible. Can uploaded data (the same in different countries or be downloaded)? (If you think the answer is Yes, you must be really secure and your data view.) (There are a lot of things that cannot be exported.) Is's your data-sharing disk with someone data? There is a chance that someone else, your data with (or without) your knowledge and exposure data, when this happens? And then there are the usual kind of service level agreement questions regarding access, up time, backup and recovery, password, password recovery, management statistics and the other daily minutia, you need it most to keep running.
Behind the cloud is still only computer - not the big and all powerful Oz-(Daten,_Datenverbindungen_und_uns_IT_Profis) but it is certainly much more, that you must consider before you there.
