Network Storage Flashcards
NAS vs. SAN
- Network Attached Storage (NAS)
- Connect to a shared storage device across the network
- File-level access
- Storage Area Network (SAN)
- Looks and feels like a local storage device
- Block-level access
- Very efficient reading and writing
• Requires a lot of bandwidth
• May use an isolated network and
high-speed network technologies
Jumbo frames
• Ethernet frames with more
than 1,500 bytes of payload
• Up to 9,216 bytes (9,000 is the accepted norm)
- Increases transfer efficiency
- Per-packet size
- Fewer packets to switch/route
- Ethernet devices must support jumbo frames
- Switches, interface cards
- Not all devices are compatible with others
Fibre Channel (FC)
- A specialized high-speed topology
- Connect servers to storage
- 2-, 4-, 8- and 16-gigabit per second rates
- Supported over both fiber and copper
• Servers and storage connect to a Fibre Channel switch
• Server (initiator) needs a FC interface
• Storage (target) is commonly referenced by
SCSI, SAS, or SATA commands
Fibre Channel over the data network
• Fibre Channel over Ethernet (FCoE)
• Use Fibre Channel over an Ethernet network
• No special networking hardware needed
• Usually integrates with an existing Fibre Channel
infrastructure
• Not routable
• Fibre Channel over IP (FCIP) • Encapsulate Fibre Channel data into IP packets • Fibre Channel tunneling • Geographically separate the servers from the storage
iSCSI
- Internet Small Computer Systems Interface
- Send SCSI commands over an IP network
- Created by IBM and Cisco, now an RFC standard
- Makes a remote disk look and operate like a local disk
- Like Fibre Channel
- Can be managed quite well in software
- Drivers available for many operating systems
- No proprietary topologies or hardware needed
InfiniBand
- High-speed switching topology
- Alternative to Fibre Channel
- Copper and Fiber options
- QSFP connectors
• Popular use in research and supercomputers
• Designed for high speeds and low latency
• 100 Gbit/sec and 200 Gbit/sec speeds are common
• Links can be aggregated for higher
throughputs (4x, 8x, 12x links)