DAS- (Direct Attached Storage)
ADAS is always preferred for Local Data Sharing Requirements
for small business.
Direct Attached Storage, or DAS, is the most basic level
of storage, in which storage devices are directly attached
to the server with drives, or directly connected to a single
server with RAID array. Network workstations must therefore
access the "server node" in order to connect to
the storage device. This have got the specialty that it’s
the first widely popular storage model. Even in today's
IT infrastructures, DAS is known for being the cheapest
and best solution when compared to other storage solutions.
Even though the implementation of networked storage is growing
at a faster rate in today's era, DAS have got its own simplicity,
cost effective with easy deployment options when compared
to other NAS, SAN solutions. As mentioned earlier when considering
DAS, it is important to know what is the exact requirement,
budget, data size, maintenance etc. But there are limitations
in DAS also. Since the storage is directly connected to
the single server, there are chances of data unavailability
for the users if the server goes down for some reason or
even if storage engineers do the maintenance. In addition
to storing and retrieving files, the server also bears the
load of processing applications. Network bottlenecks and
slowdowns in data availability may occur as server bandwidth
is consumed by applications, especially if there is a lot
of data being shared from workstation to workstation.
DAS is ideal solutions for local file sharing in environments
with a single server or a few servers - for example, small
offices, departments which do not need to share information
over long distances or across an enterprise. Small companies
traditionally utilize DAS for file serving.
With budget perspective, the initial investment in DAS is
cheaper. This is a great benefit for storage engineers who
can really do cost cutting on their storage budgets. DAS
can also serve as basic solution for those planning to migrate
to networked storage in the future. For corporate which
expects the rapid data growth, it is important to keep in
mind that DAS is limited in its scalability.
NAS (Network Attached Storage) NAS (Network Attached Storage) is
almost similar to the DAS (Direct Attached Storage) with
just the difference inbuilt software. NAS has its own OS-(Operating
Systems) and its own software. While this software is a
kind of managing software which can control the data storage,
data access to the end users and monitoring the functionalities
of the storage components. NAS units normally have their
own web interface for configuration and customization. Normally
NAS systems have the storage containers with redundancy
mode, known as RAID (Redundant Arrays of Independent Disks).
NAS systems performance is mainly based upon the network
traffic and the memory caching capability of the box.
OS (Operating Systems):
NAS unit have their customized OS operating systems which
are fine-tuned internally and nothing to do with the storage
engineer. It’s a simple box without complexities.
Software:
A NAS system has its own internal software which can be
accessed through the web interface for configuration &
management. Once the IP address gets configured it can be
managed from the network too.
Protocols:
NFS- Network File System
SMB- Server Message Block
Advantages:
End users can access the data through
network easily.
Easy configuration using web interface
& supports RAID 0,1,5
Maximum performance can be achieved
since it doesn’t have any separate server to serve
the data. It doesn’t depends on the server performance
like CPU, memory etc. It has CPU, RAM, motherboards
in its own.
With the redundancy on all the
components (like redundancy in data path, controllers,
power supplies) we can avoid single point of failures.
Limitations:
When the concurrent sessions increases
and attains the maximum CPU utilization with maximum
I/O operation level, then there will be the degradation
in the performance.
The RAM or the CPU can’t
be upgraded since it’s inbuilt within the NAS
box.
