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iSCSI

by Configure Serverov (2019-03-04)


Storage networks SAS iSCSI

SAS protocol

 

Serial Attached SCSI (SAS) is designed to replace a parallel SCSI interface and is backward compatible with SATA. It implies direct connection of storage systems and servers using copper cables - active or passive.

This protocol is optimal for small businesses, branches and business units when a full-featured low-budget solution серверное оборудование is required and no system expansion is planned in the near future. The maximum data transfer rate to the SAS protocol is limited to 12 Gb / s per line (in the future, this value will increase twice).

Pros: high bandwidth, low latency data access, affordable cost.

Disadvantages: connection to a single storage system with a maximum of up to 4 servers (due to the lack of SAS switches in the market), cable length limit is 15 meters.

ISCSI protocol

 

This is the iSCSI transport protocol, working on top of TCP / IP, which allows using the existing local area network infrastructure to connect storage systems купить . For a local network with a capacity of 1 GB, this solution will be budgetary, but ineffective. Against the background of reducing the cost of 10G switches, networks built using iSCSI over 10G Ethernet are becoming popular.

Pros: the use of existing network infrastructure, high speed of building systems, affordable cost, no restrictions on the distance between network elements.

Cons: relatively low performance, mandatory fine tuning of switches in case of high load.