Structure
SANisactuallyadedicatednetworkestablishedforstorageandindependentoftheTCP/IPnetwork.Atpresent,thegeneralSANprovidesatransmissionrateof2Gb/Sto4Gb/S.Atthesametime,theSANnetworkisindependentofthedatanetwork,sotheaccessspeedisveryfast.Inaddition,theSANgenerallyuseshigh-endRAIDarrays,whichmakestheperformanceoftheSANinseveralspecialties.Distinguishedamongthecrowdinstoragesolutions.SANisbasedonadedicatednetwork,soithasstrongscalability.ItisveryconvenienttoaddacertainamountofstoragespacetoaSANsystemortoaddseveralserversthatusestoragespace.ThroughthetapedriveoftheSANinterface,theSANsystemcaneasilyandefficientlyrealizethecentralizedbackupofdata.
CurrentlycommonSANsareFC-SANandIP-SAN.FC-SANforwardstheSCSIprotocolthroughtheFibreChannelprotocol,andIP-SANforwardstheSCSIprotocolthroughtheTCPprotocol.
Advantages
SANprovidesaneasywaytoconnectwiththeexistingLAN,andsupportsthewidelyusedSCSIandIPprotocolsthroughthesamephysicalchannel.SANisnotrestrictedbythecurrentmainstreamSCSI-basedstoragestructurelayout.Ofparticularimportanceisthatwiththeexplosivegrowthofstoragecapacity,SANallowsenterprisestoindependentlyincreasetheirstoragecapacity.
ThestructureofSANallowsanyservertobeconnectedtoanystoragearray,sothatnomatterwherethedataisplaced,theservercandirectlyaccesstherequireddata.Becauseoftheopticalfiberinterface,theSANalsohasahigherbandwidth.
BecausetheSANsolutionseparatesthestoragefunctionfromthebasicfunction,thereisnoneedtoconsidertheirimpactontheoverallperformanceofthenetworktorunbackupoperations.TheSANsolutionalsosimplifiesmanagementandcentralizedcontrol,especiallywhenallstoragedevicesareclusteredtogether.Finally,theopticalfiberinterfaceprovidesaconnectionlengthof10kilometers,whichmakesitveryeasytorealizephysicallyseparatedstoragethatisnotinthecomputerroom.
Limitations
Costandcomplexity,especiallyinFibreChannel,thesedefectsareespeciallyobvious.InthecaseofusingFibreChannel,thereasonablecostisabout50,000to60,000U.S.dollarsfor1Gigabitor2Gigabit.Fromanotherperspective,althoughthenewlylaunchediSCSI-basedSANsolutiononlycostsaboutUS$20,000toUS$30,000,itsperformancecannotbecomparedwithFibreChannel.ThedifferenceinpriceismainlyduetothefactthatiSCSItechnologyusesGigabitEthernethardwarethathasbeenmass-produced,whileFibreChanneltechnologyrequiresspecificexpensiveequipment.
Applicableenvironment
SANismainlyusedinworkingenvironmentswithlargestoragecapacity,suchasISPs,banks,etc.ThehighcostandundecidedstandardshaveaffectedtheSANmarket.However,asWiththeincreaseinthebusinessvolumeoftheseusers,SANalsohasawiderangeofapplicationprospects.