This post I would like to overview about the different type of storage technologies including Direct-attached storage (DAS), Network storage, storage virtualization, flash technology and cloud computing, and the components and protocol that underlie those technologies. Furthermore, the benefits and which type of environment would be best-suited for that technology.
Direct-attached storage (DAS):
DAS is the digital storage system that is directly connected to one computer or server without any storage network in between, and it is not accessible to other clients and servers machines. Example, Hard drive is the form of direct-attached storage for an individual user. DAS can be a disk on a server, Disk in a client, group of disks internal or external to a server.
In the enterprise solution, individual disk or group of disks that are internal or external are directly attached to a server through SCSI, SATA and SAS interfaces.
- It can provide better performance than network storage because of the dedication server
- Server does not need to traverse the network in order to read and write data
- Proper utilisation of underlying storage during expansion of application server
- It is one of the famous cost effective solutions for any small organisation
- Small business organisation or enterprise
- Small or home office users
- Localised file sharing with single or few servers in an infrastructure
- Certain type of application that needs high performance
For the organisation that anticipates rapid data growth, it is important to keep in mind that DAS is limited in its scalability.
Criticised: An inefficient way to manage storage because DAS can’t be shared and it has not failover facilities if server crash occurs. However, the advantages of the DAS has gained again as virtualization become mainstream.
Network-attached storage (NAS):
It is a kind of dedicated file storage devices that provides local-area network nodes with file-based shared storage through an Ethernet connection. NAS has a processor, Disk array using RAID technology for handling disk failure, the external disk can be connected to NAS system for additional storage. For managing and configured NAS devices do not need a keyboard or a monitor, it can be a browser-based utility program.
From both a cost perspective and an administrative perspective, network storage models such as NAS and SAN are more suited to high scalability requirement and can address the challenges inherent in a DAS implementation.
- Ethernet switch
- Own IP address
How a NAS system functions?
- Each NAS must reside on the Local area network as an independent network node
- On a network, the NAS system appears on a file server with an IP address
- The NAS implements file services by using protocols of CFS and NFS
- The application servers handle all the processing of data
- NAS provide multiple clients to access the same files on the network
- NAS appliances can be outfitted with larger disks or clustered together which provide both vertical scalability and horizontal scalability
- File-based storage system that makes data available over the network
- NAS relieves the server of storage and file sharing responsibility
- NAS vendors with cloud storage provider may provide customer with an extra layer of redundancy for backup files
- More flexible to data access
Ideal for business organisation who wants to
- Easy to manage, Install and deploy
- Implementing multiple clients at the file level to get access to faster data in a cost effective way
- Consolidate DAS resources for better utilisation
Storage Area Network (SAN):
It is a dedicated high-speed network storage that interconnects and maintains shared pools of storage devices to multiple servers. It allows each server to access shared storage even through disk drives directly attached to the server. It is blocked based storage system that transfers data between servers and storage devices on request from the user end. A host sends out a block- based access request when it wants to access storage on the SAN.
- Host bus adapters (HBAs)
How does it function?
- Each switch and storage system must be interconnected
- Physical interconnections must support bandwidth level so that they can handle peak data activities effectively
The different type of SAN:
- FC-SAN (Fibre Channel) – most common
- iSCSI SAN – Standard IP-based storage access protocol
- FCoE SAN – Fibre Channel over Ethernet
Best suited environment:
- High data growth Database and Imaging server
- High volume Transaction processing
- High performance and 24/7 operation
Storage virtualization consists of taking several physical storage devices and joining them to appear as one logical unit to manage.
The benefit of storage virtualization:
- Increase storage utilisation: It is easier for an administrator to managing all of the spaces including in the pool apart from its location by pooling storage into a single resource. This permits for much better storage utilisation.
- Simplify storage management: Storage management is also easier because virtualization storage can be managed from a single administrate console. A storage administrator can see utilisation trends and growth patterns more clearly and can make better upgrade or capacity planning decisions. Virtualization storage can be thinly provisioned or even dynamically provisioned (increasing or decreasing the storage on demand)
- Increase storage flexibility: Virtualization storage is also flexible when storage space is decoupled from a physical disk or storage arrays. It’s simple to migrate and copy that virtual storage between systems or geographic locations. For example, the data can be migrated from an older storage system to a newer one for the better performance without making any adjustments to the application. Similarly, data can be copied to another local storage system for backup purposes or replicate to an off-suit location for disaster recovery purposes.
The advantage of flash storage:
- Memory unit: Stored data
- Access controller: Manages and controls access to the storage space on the memory unit
- Superior speed
- Reliable compare to traditional disk and unlike traditional disk, it uses electricity and read faster
- Flexible, Cost-effective, Optimise storage
The advantage of Cloud computing:
Private cloud computing:
- Relay heavy on own data and applications
- Have a restricted data security and privacy requirement
- Can run a need-generation cloud data center efficiently and effectively on own system.
Disadvantage: Organization has to purchases and maintains all software and infrastructure
Public cloud computing:
- The services and infrastructure are rendered off-site over the internet and are open to public
- It offers the greatest level of efficiency in shared resources
- Users don’t need to purchases hardware, software, or any supporting infrastructure because those resources are owned and managed by providers
Disadvantage: Public cloud is more vulnerable than private cloud in term of security and reliability
Hybrid cloud computing: It is a combination of private and public options. It can be the best choice for an organisation who offers services that are tailored for the different vertical market because the business can use a public cloud to communicate and connect with their clients and keep own data secure within a private cloud.
- With multiple providers offering the benefit of multiple deployment models
- Users can keep each aspect of their business in the most efficient environment
Disadvantage: Users have to keep track of multiple different security platforms and ensure that all aspects of their business can communicate with each other.
Question: A CEO of the organisation comes to you for a storage solution for his company. As per his requirement, the company has 1200 employees, maintained 8 separate servers for 8 different applications, they have a file server, mail server, database server and in hours software server. Their data growth rate is GIGAbytes per hours. What is the best solution you would give him and why?
Answer: The best suggestion I would like to give him to reduce the number of physical servers by using the virtualization storage. It would help him to reduce managing and maintain cost, administrative and controlling server would be easier for the company. Based on his data growth rate and access to operation time Storage Area network SAN would be best suited for that company because it allows each server to access shared storage even through disk drives directly connected. It is high-speed network storage and maintained a shared pool of multiple servers. It is the best solution for that company has usage data growth database server and live operation 24/7, also required high performance.