STORAGE TECHNOLOGY 
With the development of information technology and the explosion of data, the preservation and storage of data safely and efficiently are needed. So that the storage solution was born to meet the needs of the user.
Due to increasing amounts of data, increasing requirements on access performance, stability and availability of data; the storage has becomevery important. Data storage is not only simply providedstorage capacity but also including the ability to manage, share and backup anddata recovery in all cases.
For data storage we can usemany different devices, many different technologies. The data warehouse can be used hard disk, using magnetic tape, opticaldisc ... Depending on the specific requirements we choose the suitable technology and equipment. Following the storage structure, there are some kinds of basic data storagesuch as:
- DAS : Direct Attached Storage
- NAS: Network Attached Storage
- SAN : Storage Area Network
Direct attached storage - DAS
DAS (Direct attached storage) is computer storage directly attached to the server. This is the traditional technology which most of enterprise using. With the DAS structure, each severs has each of storage system and private storage software.
The advantages of DAS solution is the ability to easy installation, low cost, high performance.
However, the disadvantages of DAS are limited scalability. In fact, DAS operate very well with a server but when the data increases, the number of severs will also increase and make the data dispersed and interrupted. Meanwhile, administrators would have to supplement or re-establish capacity, and maintenance work will be done on each server. That will increase the overall cost of storage for enterprise and will become more difficult to protect a backup or archive system data are scattered and dispersed.
Network attached storage - NAS
NAS (Network attached storage) is a method of storing data using a special storage device attached directly to the LAN as a normal network device (similar to the computer, switch or router). NAS devices also assigna fixed IP address and user access via the server's control.In some cases, the NAS can be accessed directly without the management of the server.
In the multi – operating system environment with many different servers, the data storage, backup and restore data, manage or apply security policy are made to focus.Advantaged of NAS
- Scalability: When users need more storage space, the new NAS appliancestorage can be added and installed in thenetwork.
- NAS provides ability to fight for a network problem.In DAS environments,when a dataserver may not work the entire measurementdata cannot be used. In the NAS environment, the datacan be fully accessed by the user. Measures against error and advanced redundancyare applied to ensure NAS are on hand to provide data to users.
- Use infrastructurenetwork with the other applications, the data storage may affect the performance of the whole system (slow speed of the LAN), this specialconsiderations are concernedwhen need regular storage large amounts of data.
- In the environmental of database systems, the NAS is not a good solution because the system database administrator usually save the data in the form of block as a file rather than use the NAS will not for performance.
Storage Area Network - SAN
SAN (Storage Area Network) isa high-speed private network for data transmissionbetween the servers involved in the storage system as well as the storage devices. SANallows centralized management and provides the ability to share data and storage resources. Most current SAN network base on fiber channel technology, offers users the scalability, performance and high availability.
SAN system is divided into two levels: physical and
logical
• Physical level: describes the links of network parts create storage system
and can be used simultaneously for many applications and users.
• Logical level: including the applications, the management tools and services
built on the foundation of the Physical layer device, the ability to provide
SAN management system.
Advantaged of SAN
- The ability to back up data with the frequency and large amount not influence the network information.
- SAN is particularly suitable for applications that need speed and reduced latency applications such as transaction processing in banking and finance
- The data always high availability.
- The data is unified storage, centralized and highly capable management. Able to recover data if problem occurs.
- Support for multiple protocols, different storage standards like ISCSI, FCIP, DWDM ...
- The ability to expand on the aspects good amount of equipment, system capacity as well as physical distance.
- The safety level focus on the management as well as use the support tools to manage SAN.
Therefore, the SAN is often used in large data centers because it was carrying some features such as: risk reduction for the data, the ability to share resources is very high, the ability to easily develop, throughput large, supporting a variety of devices, supporting and managing the transmission of large data and high data security.
Furthermore, SAN enhance the performance system by supporting multiple operating systems, server and the application, able to respond quickly the changes about the operational requirements of an organization as well as the technical requirements of the network.EVALUATE STORAGE SOLUTION
The advantages of DAS solution is the ability to easy installation, low cost, high performance. Disadvantages of DAS are limited scalability: when the data increase the number of servers also increased. This will make the disperse data, interruption and difficulty back up as well as protection storage systems.
The NAS and SAN solution solve the disadvantages of DAS. With the NAS and SAN storage, the storage is separated from the server, incorporated in the network, creating a wide area access to the server, usersand applications accessor exchange. It creates flexibilityand dynamism. The management and data protection will become simpler, convenient, and low cost. NAS suitable with the share file environment but restrict in the databasesystem environment. Moreover, NAS made the speed network access low and affect overall system performance when using the network infrastructure with other applications.
SAN network storage solution solves the limitations of NAS and particularly suitable for applications which need high speed with little latency. Moreover, SAN able to respond quickly to changes on the operational requirements of an organization as well as the technical requirements of the network. However, disadvantages of SAN are the investment cost is higher than both DAS and NAS solutions.
THE ABILITY OF STORAGE SOLUTION
Until this time, Using DAS, NAS, SAN solution is gradually changed. In the past, DAS is the most popular storage solutions. However, the current trend is transferring to the NAS, SAN and new FCoE technology.... With many years experience in the IT field, our company guarantees to provide customers the storage solutions with multiple levels suitable with the demanding but always pay attend on:
- The best solution of a storage system must be able to integrate all kinds of storage technologies, storage devices and can support many types of storage.
- Reviewing and catching the technology trends of the big manufacturers in order to provide the best storage service for customers.
- The system must satisfy the storage requirement now and future.
- The system has high availability and high enforces application.
- The solution can open widely and uninterrupted development while ensuring reasonable investment.
- Solutions are perfect and professional service system.
- Easy to deployment and administration: The management software will simplify management tasks and reduces operating costs.
Model of Storage system symbol
