Storage Types Overview
Direct Attached Storage (DAS)
DAS is the simplest storage type, where a storage device is directly attached to a host device (e.g., an external hard drive connected to a PC). DAS provides the best performance and low latency but has limited expandability and is not suitable for sharing storage across multiple users/devices. Common DAS connectivity options include USB, SATA, eSATA, and SAS.
Network Attached Storage (NAS)
NAS is a file-level storage solution that provides storage over a network, allowing multiple users/devices to access the storage simultaneously. NAS devices typically use networking protocols like SMB (Server Message Block) or NFS (Network File System) to provide storage access. NAS solutions often use RAID configurations to provide data redundancy and increased capacity.
Storage Area Network (SAN)
SAN is a dedicated, high-speed network that interconnects storage devices and servers, providing block-level storage access. The most common SAN protocols are:
- Fibre Channel (FC): The de facto standard for SAN interconnects, providing high-speed, low-latency data transfer.
- iSCSI (Internet Small Computer System Interface): An alternative to Fibre Channel that uses standard Ethernet networks.
- FCoE (Fibre Channel over Ethernet): A protocol that places Fibre Channel traffic over Ethernet networks.
- FC-NVMe (Non-Volatile Memory Express over Fibre Channel): An interface protocol for accessing flash storage via Fibre Channel.
SANs are designed to provide high performance, reliability, and scalability for business-critical applications.