2012華科博士英語真題

2012真題

Cloud Storage Basics

Comedian George Carlin has a routine in which he talks about howhumans seem to spend their lives accumulating "stuff." Once they'vegathered enough stuff, they have to find places to store all of it. If Carlinwere to update that routine today, he could make the same observation about computerinformation. It seems that everyone with a computer spends a lot of time acquiring data andthen trying to find a way to store it.

For some computer owners, finding enough storage space to hold all the datathey've acquired is a real challenge. Some people invest in larger harddrives. Others prefer external storage devices likethumb drives or compact discs. Desperate computer owners might deleteentire folders worth of old files in order to make space for new information. But some arechoosing to rely on a growing trend: cloud storage.

While cloud storage sounds like it has something to do with weather fronts and stormsystems, it really refers to saving data to anoff-site storage system maintained by a third party. Instead of storinginformation to your computer's hard drive or other local storage device, yousave it to a remote database. The Internet provides the connection between your computer andthe database.

On the surface, cloud storage has several advantages overtraditional data storage. For example, if you store your data on a cloudstorage system, you'll be able to get to that data from any location that hasInternet access. You wouldn't need to carry around a physical storagedevice or use the same computer to save and retrieve yourinformation. With the right storage system, you could even allow other peopleto access the data, turning a personal project into a collaborativeeffort.

So cloud storage is convenient and offers more flexibility, but howdoes it work? Find out in the next section.

There are hundreds of different cloud storage systems. Some have a veryspecific focus, such as storing Web e-mail messages or digital pictures. Others are available to storeall forms of digital data. Some cloud storage systems are small operations,while others are so large that the physical equipment can fill up an entirewarehouse. The facilities that house cloud storage systems are called datacenters.

At its most basic level, a cloud storage system needs just one data server connected to the Internet. A client (e.g., a computer user subscribing to acloud storage service) sends copies of files over the Internet to the dataserver, which then records the information. When the client wishes to retrievethe information, he or she accesses the data server through a Web-basedinterface. The server then either sends the files back to the client or allowsthe client to access and manipulate the files on the server itself.

Cloud storage systems generally rely on hundreds of data servers.Because computers occasionally require maintenance or repair, it's importantto store the same information on multiple machines. This is called redundancy.Without redundancy, a cloud storage system couldn't ensure clientsthat they could access their information at any given time. Most systems storethe same data on servers that use different powersupplies. That way, clients can access their data even if one power supplyfails.

Not all cloud storage clients are worried about running out of storage space.They use cloud storage as a way to create backups of data. If something happensto the client's computer system, the data survives off-site. It's a digital-agevariation of "don't put all your eggs in one basket."