high-end storage

Data is the essence of a company, and it needs to be protected as aggressively as possible.  Just what is the difference between DAS, NAS and SAN technologies?

Direct Attached Storage
DAS means each server has dedicated storage that is directly connected to that device.

The storage device is seen and accessed by a single host system, and in the event that another host system will need additional storage, that host will add more physical storage and/or I/O interfaces or host bus adapters. This model offers an alternative solution to NAS and can be used, designed and implemented with various vendor storage and management interfaces.

Network Area Storage

What is a NAS?
NAS (Network Attached Storage) is disk storage that connects directly to a messaging network via a LAN interface such as Ethernet.

• NAS devices are a great solution for small workgroup settings.
• Immediate, low cost solution for desktops without sufficient storage.
• Higher end NAS units allow for RAID and tape options.

Computer systems can access data from a NAS appliance over a network via a file "redirector" that changes the access to a file from the native file system (on the originating computer system) to a network operation using TCP (Transmission Control Protocol) to a remote server that is running software to provide the file system to support the individual client access. The file system on the NAS server determines the location of the data requested by the application client whether it is in its cache or on the storage.

• Features
  Works independently without host support Centralizes storage control Provides fast, easy installation and administration Usually improves network throughput Offers a potentially lower cost alternative Provides cross-platform file server Operates unattended with low data security risk Fast time to data – fast recovery, minimal downtime.
  
  NAS features provide organizations of any size the ability to install NAS and have it up and running in minutes with minimal interruption of service to end- users.
  
  

Storage Area Network

What is a SAN?
A storage area network (SAN) is a high-speed special-purpose network or separate sub-network. SANs support disk mirroring, backup and restore, archival and retrieval of archived data, data migration from one storage device to another, and the sharing of data among different servers in a network.

• SAN Fabric
  The SAN fabric consists of two or more interconnected Fibre Channel switches that connect to Fibre Channel storage devices.
   
• Management
  There are two ways to integrate management into this scenario. The first is to directly manage the devices, either through their own management interface or through a third part application. The rest of the network devices and infrastructure are managed through standard SNMP interfaces.
   
• Servers Connection to Fabric
  Fibre Channel HBAs (Host Bus Adapters) are intelligent interface cards that will physically make the connection to the switches as well as provide the necessary interface to the operating system.
   
• Connecting the HBA and Switches
  Both copper and fiber optics are viable solutions. Each has it's own benefits and features to be considered. Basically cooper is less expensive, but fibre optics provide a reliable connection over long distances.
   
• SAN Security Issues
  SAN solutions are secure. In association with a SAN management station, certain policies can be designed that will protect the network and data from unauthorized use or intentional damage.