National Day Rookie School: An analysis of the terminology of enterprise storage

DAS, Nas, and San three storage

For storage, many people still stay in the simple hard disk, memory, with the rapid development of the network era, storage technology constantly updated, storage has long been in the hard disk technology based on the rapid development. Now that enterprise-class storage technology is constantly pouring into the marketplace, making it difficult for users to perceive professional terminology, such as networked storage, virtual storage, cloud storage, data deduplication, archiving technology, and so on, are these technologies confusing?

While mastering these terms does not seem to be practical for most people and does not really mean familiarity with industry technology, these basic storage terms can help people who want to gain a deeper understanding of enterprise storage technology to get started.

When it comes to data storage, the first thing to think about is the hard disk, because the data is basically stored in the disk, for its data preservation plays a certain effect. For enterprise users, server data storage is relatively more important, some even determine the fate of the enterprise. With the increase of data in enterprise Network application, the concept of networked storage technology comes into being.

DAS, Nas, and San three types of storage

First, DAS (direct checkmark Storage, directly externally stored) is a method of storage. The server structure of this storage scheme is like the PC architecture, the external data storage devices (such as disk array, CD-ROM, tape drive, etc.) are attached directly to the server's internal bus, the data storage device is part of the whole server structure, the same server is responsible for the data storage of the whole network.

In addition, DAS can also constitute a disk-based dual-computer highly available system to meet the high availability of data storage requirements.

Second, NAS (receptacle checkmark Storage, network-attached storage) comprehensively improves the previously inefficient DAS storage, which is a file server developed independently of a PC server and isolated for networked data storage. NAS servers are centrally connected to all network data storage devices (such as a variety of disk arrays, tapes, optical discs, etc.), storage capacity can be well expanded, and because this type of networked storage is independent of the NAS server, so, the original network server performance basically has no effect, To ensure that the overall network performance is unaffected.

Sans (Storage area receptacle, storage domain networks) instead of concentrating all storage devices on a dedicated NAS server, they are connected to each other through fibre switches to form a Fibre Channel network. The network then connects to the enterprise's existing LAN.

In this scenario, the core role of course is the fiber-optic switch, its support technology is the Fibre Channel protocol, which is ANSI for network and channel I/O interface to establish a standard integration, support HIPPI,IPI,SCSI,IP,ATM and many other high-level protocols. In a SAN, data is stored in a centralized manner, enhancing the manageability of data, while adapting to the same storage pool for data sharing under multiple operating systems, reducing total cost of ownership.

What is virtual storage and cloud storage

What is virtual storage and cloud storage

Once you know how to store the basics, you'll be more aware that many of the technologies and products in enterprise-class products are built around them. The most popular of these days is virtualization and cloud technology, and storage is a good place to apply these two concepts separately.

In the technical level, it is difficult to specifically the virtual storage thorough detailed. However, from a popular definition point of view, virtual storage is the virtualization of the storage system. In fact, virtualization technology is not a very new technology, its development, it should be said that with the development of computer technology, since the virtual storage technology has a long history, that how to understand today's popular virtual storage applications?

The concept of a more popular understanding, is to put more than one hard drive, raid through a certain means of centralized management, all the storage modules in a single storage pool to be unified management, this can be a variety of storage devices unified management, to provide users with large capacity, high data transmission performance of the storage system, called virtual storage.

In addition, the virtual storage technology can provide some other useful functions for the network system through the management software, such as simplifying the remote mirror of the server, snapshot and other applications.

Cloud storage is affected by cloud computing

And when it comes to cloud storage, cloud computing is being impacted, and as the data center grows on cloud applications and demand, clouds are also stored in the cloud's data center. The latest craze for cloud storage applications is primary storage services, most notably San and NAS. In both environments, local storage plays the role of the cloud storage cache in primary storage. As data is updated, it is replicated to the cloud, which is similar to how snapshot replication is used in traditional systems. Records for the data are saved only in a cloud copy. This allows the application or user to move to the cloud storage area, and the data is replicated back to the cache for reading by the user.

It may not be intuitive and simple enough to say that cloud storage is a new technology or service derived and developed in the cloud computing concept, which combines distributed processing, parallel processing, and network computing. Through the network to automatically split the computer processing program into countless smaller subroutines by a large number of servers composed of the calculation and analysis of the results returned to the user.

And cloud storage is the network of various types of storage devices through the application software together to work together to provide data storage and business access functions of a system. Cloud storage is composed of 4 layers: storage layer, base management layer, application interface layer, Access layer.

Data deduplication and archiving technology

Data deduplication and archiving technology

The ultimate goal of storage is to effectively use data, whether virtual or cloud storage, all need to combine good data technology, effectively processing data so that it can meet the needs of enterprise users. The most important work in storage is the need for late backup, and the continuous expansion of data duplication, how to further generate value through these data, enhance business capacity to increase efficiency is the key.

Data deduplication is a data reduction technique designed to reduce the storage capacity used in the storage system. Depending on how the data is processed, the de-duplication technique can be divided into two types: one is online processing (cross-references), in which data is deleted before it is read, and is removed before it is stored to disk; the second is post processing (post-processing), in which case , data is not deleted until it is saved to disk, and the data is not reduced until it is saved to disk.

Each of these approaches has advantages and disadvantages: The advantage of cross-references is that it saves disk space while duplicating data deletion step is particularly simple. But the disadvantage is that the CPU loss is very large, will occupy a lot of CPU resources, resulting in performance degradation. By contrast, post-processing is a lot less CPU-intensive, but the flaw is that duplication of data deletion is more complex.

However, the explosive growth of data volume, said storage is not simple to save and store the meaning, but involves backup, data archiving, data protection, data mining and so on, and in these storage scope, data archiving is the most commonly mentioned technology.

How to understand data archiving

For data archiving, a consistent copy of a data collection that is typically used to persist transactions over a long period of time or to apply state records. Typically, data archiving is often used for auditing and analysis purposes, rather than for application recovery purposes, and data archiving and backup are the application forms of data storage, and are used only for different purposes.

A backup is a replication of data to ensure that the replicated data is recovered when there is a data loss or system disaster, so it is well understood to look at the data archive based on the explanation of the backup. Data archiving is an application of massive data and a planned migration of data. When data is stopped or not being used frequently, transferring them to other places via data archiving, freeing up primary storage and keeping it out of the daily Backup window saves space and improves backup efficiency.

So according to the above explanation, if it's simpler, it's the difference between CTRL + C and CTRL, the backup is copy, and the data archive is cut. For enterprises, backup and data archiving has two different but complementary features: backups are used for rapid replication and recovery to reduce the impact of failures, personnel errors, or disasters; Data archiving is used for effective management, retention, and long-term access and retrieval of data.