NAS for files, SAN for blocks
NAS provides file-level access over NFS or SMB. SAN provides block-level access that appears as a local disk to the server.
6.4 NAS and SAN
Load balancers distribute traffic across servers. Storage appliances provide the persistent data layer that those servers depend on.
NAS and SAN
Section titled “NAS and SAN”| Feature | NAS (Network Attached Storage) | SAN (Storage Area Network) |
|---|---|---|
| Access type | File-level (NFS, SMB) | Block-level (Fibre Channel, iSCSI) |
| Network | Standard Ethernet | Dedicated FC or Ethernet |
| Appears as | Network share | Local disk |
| Use case | File sharing, backups | Databases, virtual machines |
iSCSI (Internet Small Computer Systems Interface) encapsulates SCSI storage commands in TCP/IP, allowing SAN access over standard Ethernet without dedicated Fibre Channel infrastructure.
Key Takeaways
Section titled “Key Takeaways”iSCSI runs SAN over Ethernet
iSCSI eliminates the need for dedicated Fibre Channel infrastructure by encapsulating SCSI commands in TCP/IP.
What Comes Next
Section titled “What Comes Next”Standard IT appliances handle general-purpose security and storage. The next page covers OT-specific appliances: industrial firewalls with deep packet inspection, data diodes, and protocol-aware filtering.
References
Section titled “References”- CompTIA Network+ N10-009 Exam Objectives, Domain 1: Networking Concepts