A Survey on Network Storage

Ning Zong

Haibin Song

Richard Alimi

Richard Yang

Network Storage System Components

Network StorageNetwork Storage

Client

(1) Discovery

(5) StorageMode

(6) Operational Model

(3) Operations(4) Access &

Resource Control

(2) Access Protocol

NFS (Network File System)

NFS allows a user on a client computer to access files over a network in a manner similar to how local storage is accessed.

pNFS allows clients to access storage devices directly and in parallel.

NFS Client NFS Client NFS Client

NFS Server

Doesn’t provide resource control (bandwidth and connections) Access control with many P2P peers is difficult

Web Cache

Deployed between web servers and clients to save copies of server responses for future reuse to reduce latency and network traffic.

HTPT: Proposal to share chunks of P2P files/streams using HTTP protocol with cache-control headers.

web Client

web Client

web Client

web Server

web Server

web cache

Req (URL_1)

Req (URL_2)Resp (Page_A)

Resp (Page_B)Req (URL_1)

Resp (Page_A)

Doesn’t provide resource control (bandwidth and connections) Access control with many P2P peers is difficult

Transparent P2P Cache

Allows duplicate P2P content to be cached and supplied locally Impersonates P2P peer → requires support of P2P application

protocols Another option: modify peer list to include cache Upstream and downstream traffic reduction Use of DPI means no discovery needed by application

Doesn’t provide resource control (bandwidth and connections) Cache is complicated due to the evolving P2P applications

Non-Transparent P2P Cache

Allows duplicate P2P content to be cached and supplied locally

Operates as traditional P2P peer → requires support of P2P application protocols

Doesn’t provide resource control (bandwidth and connections) Cache is complicated due to the evolving P2P applications

CDNs (Akamai, Limelight, CloudFront) Allows content to be

distributed globally Push contents to network edge Lower latency, reduces

upstream bandwidth requirement by content owner

Doesn’t provide resource control (bandwidth and connections) Access control with many P2P peers is difficult

Amazon S3

Online storage service Users create buckets; buckets

contain stored objects Popular backend storage for

other services

Doesn’t provide resource control (bandwidth and connections)

Windows Azure

Storage for distributed (cloud) applications

BLOB Service API supports storage of binary data

Doesn’t provide resource control (bandwidth and connections) Access control with many P2P peers is difficult

OceanStore

Globally distributed storage Multiple storage providers pool

resources together Focus on resilliency

Doesn’t provide resource control (bandwidth and connections) Doesn’t support explicit control over location of data in the network

ISCSI (Internet Small Computer System Interface) Protocol for carrying SCSI

commands over IP Popular for Storage Area

Networks

Doesn’t provide resource control (bandwidth and connections) Access control with many P2P peers is difficult

Q&A

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