Difference Between DAS and SAN

1. Directly Attached Storage (DAS) :
The storage device which is permanently attached to a desktop computer. DAS is for a single user (Hard drive attached to a computer). It is well suited for a small-to-medium sized business where sufficient amounts of storage can be configured at a low startup cost. The DAS enclosure will be a separate adjacent cabinet that contains additional disk drives.

Component of Directly Attached Storage (DAS) –

1. Storage devices
2. Cables
3. Disk Array
4. Protocol
5. Storage protocols: ATA, SCSI, SAS, SASA, FC 

2. Storage Area Network (SAN) :
SAN acts on block level over network. Storage which can be accessed using ISCSI or FC. Suitable for business-critical applications and where high performance is required. The main benefit to a SAN-based storage solution is ability to share storage arrays to multiple servers. This allows you to configure storage capacity as needed, usually by a dedicated SAN administrator. Higher levels of performance throughput are typical in a SAN environment, and data is highly available through redundant disk controllers and drives.

Components of Storage Area Network (SAN) –

1. Node ports
2. Cables
3. Interconnect device such as: Hubs, switches, directors
4. Storage arrays
5. SAN management Software 

Difference Between DAS and SAN :

SR.NO	DAS	SAN
1.	DAS stands for Direct Access Storage.	SAN stands for Storage Area Network.
2.	For backups and recovery, Sectors are used.	For backups and recovery, Block by block copying technique is used.
3.	It is easy to install.	It is difficult to install.
4.	It is not complex.	It is complex.
5.	It is less expensive	It is more expensive.
6.	For data transmission, IDE/SCSI is used.	For data transmission, Fiber Channel, IP is used.
7.	Its capacity in bytes is 10^9.	Its capacity in bytes is greater than 10^12.
8.	It does not allow to share files at different operating system.	It allows to share files at different operating system.