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DNS (Domain name system) is the most critical infrastructure on the internet. Each and every user connected to the internet, knowingly or unknowingly make hundreds of DNS queries each and every day. So in a way, internet is almost of no use without the system called as DNS. The only way you can make use of internet without DNS, is to memorize all the numerical IP addresses associated with each and every domain(not only you will have to memorize, but will have remember which IP address is for which domain. So its an impossible task, and lets not discuss it).

If you are interested in understanding the basic working of a DNS query and how a server responds to that query, or in other words, if you want to understand how a computer uses a DNS server to resolve domain names to IP addresses, then i will recommend reading the below post.

Any internet based service company like for example web hosting, DNS hosting, Email-hosting, Cloud architectures, and even CDN networks have server's ranging from several hundreds to thousands. There might be different roles that are played by different servers that are geographically isolated from each other. As a whole these geographically separated servers might be providing a combined service to the end customer. A particular issue or problem on any of the server should not affect the customer service, and must be found and fixed before the outage happens.

Creating, deleting, and modifying files is one of the common task that a user does in any operating system. This kind of task comes under a day to day list of tasks that a user does. Although it is quite fast and seamless operation when it comes to deleting a single or a handful of files in Linux or any other operating system. But if the number of files is quite large, then the deletion operation takes quite long to complete.

The brain of any operating system is its kernel. But a computer with only an operating system(kernel) is of no use, because nobody really uses an operating system. The end user of a computer is always concerned about programs, and not the operating system.

What an operating system really does is to provide an environment, where these programs can run. So the only job of an operating system is to provide resources to program's, so that the program can complete its task. People forget the difference between programs and operating systems, simply because, modern day operating system installs a good number of programs along with the operating system itself.

Our introductory guide to NFS did not contain some major topics, that requires special attention when we talk about NFS. These topics must always be given an extra bit of care, while configuring NFS. We purposely skipped out most of the serious topics in NFS in that tutorial guide, because of the simple reason that they are serious topics and must always be discussed separate. For those who did not read our NFS introductory guide, i will recommend reading that before beginning this tutorial.

Read: NFS(Network File System) in Linux

During the infancy period of computer's, SUN Microsystems developed a technology, which made accessing files from other computer's over network easy. This technology gave a new dimension to access data through network, and is heavily used even today in organizations. The advantage of this technology is the fact that it made directories and partition's on remote system's available as if it is a local directory or file system.

Most of the computer users out there must have felt a need for increasing or decreasing (resizing) partition size after it is created, at least once. And if you are working in a production environment you might at times need to make a large partition, by combining small hard disks of various size, so that, it appears as one large hard disk/partition to the operating system.

The above mentioned things can be achieved by a technology called as Logical Volume Management or commonly known as LVM. Heinz Mauelshagen wrote the initial code for LVM that works on a HP Unix system. Later on, all modern day Linux distributions began to use it as a mechanism to provide flexibility in storage by providing the capability to resize, and combine multiple physical hard disks of various size to a single logical volume, for the operating system to use.

Most people ask why is database so faster when compared to flat file entries of data. There are many reasons behind that, one of them is indexing. Of course the speed of the underlying disk subsystem's also plays a major role in increasing database speed. Due to the heavy use of Relational database in almost all companies that employ heavy database, it has become very important to understand the internal working of the database, or i must say what factors makes a database efficient in terms of performance.

Let's get back to some computer basics before getting inside indexing in databases.