Introduction
SincethebirthoftheCD-ROMstandardforrecordingcomputerdataonCDdiscs,CD-ROMdiscshavebeencharacterizedbytheirlargecapacity,lowcost,standardizeddataformat,easystorageandsafetyTheincomparableadvantagesoftraditionalrecordingmedia,suchasreliability,convenienceandportability,havebecomeanindispensableinformationcarriermediumintoday'sinformationsociety.
Advantages
CD-ROMisverysuitableforthestorageoflarge-capacitydatainformation,especiallysuitableforthestorageofvariousmultimediainformation.Atpresent,CD-ROMisthepreferredstoragemediuminthepublicationanddistributionofcomputersoftware,e-books,filmandtelevisionprograms,educationalmaterials,andvariousdatabases.WiththerapidgrowthofthenumberofCD-ROMdiscsinvariousorganizations,howtomanageandusethesehugenumbersofdiscssafely,conveniently,andeffectively,especiallyhowtousecomputernetworkstoefficientlyandsecurelysharethemhasbecomeeverydiscwithalargeamountofdata.Thetoppriorityofunitsandinstitutions.
Classification
Atpresent,therearethreetypesofequipmentforCD-ROMsharingthroughthenetwork:CDtower,CDlibraryandCDmirrorserver.Thesethreekindsofdevicesaretypicalopticaldiscsharingdevicesthatappearedindifferentperiods.
CD-ROMTower
TheCD-ROMTowerismadeupofmultipleCD-ROMdriveswithSCSIinterfacesinseries.TheCD-ROMisplacedintheCD-ROMdriveinadvance.Infact,itisequivalenttothe"stacking"ofmultipleCD-ROMdrives.ThenumberofCD-ROMdiscsthatthedisctowercanshareatonetimeisequaltothenumberofCD-ROMdrivesitowns.WhentheuseraccessestheCD-ROMtower,theCD-ROMintheCD-ROMdriveisdirectlyaccessed,andtheaccessspeedisslightlyfasterthanthatoftheCD-ROMlibrary.
CD-ROMJukebox
ThedesignideaoftheCD-ROMJukeboxisderivedfromthecoin-operatedjukebox.Itisadiscnetworksharingdevicewithanautomaticdiscchangingmechanism(manipulator).Theopticaldisclibraryisgenerallyequippedwith1~12CD-ROMdrives,whichcanhold50~600CD-ROMdiscs.WhentheuseraccessestheCD-ROMlibrary,theautomaticdiskchangemechanismfirsttakesouttheCD-ROMthathasbeenplacedintheCD-ROMandplacesitinthedesignatedpositiononthediskrack,andthenremovestheCD-ROMdiskrequiredbytheuserfromthediskrack,andthenThisdiscisfedintotheCD-ROMdrive.Sincethediscchangingtimeoftheautomaticdiscchangingmechanismisusuallyontheorderofseconds,theaccessspeedofthedisclibraryistheslowestamongthethreediscsharingdevices.
Mirrorserver
(CD-ROMMirrorServer)
Likefileserverorprintserver,CD-ROMmirrorserverisakindof"thinserver".Itusesharddiskcachetechnologytostore(mirror)thecontentoftheentiredisctotheharddisk.Inthisway,userscansharethemirroredCDintheserveratthespeedoftheharddisk.
Devicecomparison
Devicename,accessspeed,capacitycost,numberofusersthatcanbesharedandusedatthesametime
Opticaldisctowermedium,minimum,high,smallamount
CDlibraryisslow,maximum,maximum,smallamount
TheCDmirrorserverisverylargeandthelowestismuchfaster
Technicalfeatures
Speedadvantage
1,CDMirrorserverisakindofnetworkattachedstoragedevice(NetworksAttachedStorage,NAS)isawaytosolvetheslowspeedandserviceinterruptionphenomenonintheconventionalfileservermodel.Theopticaldiscmirroringserver(suchaseLake®VCLseriesproducts)thatadoptsnetwork-attachedstoragetechnologyhasthefollowingobviousadvantages:(1)Improvethefileservicespeedandgreatlyreducetheburdenonthenetworkhost;
(2)Plugandplay,VCLandotherproductsonlyneedtopluginthepowersupplyandaRJ45linetouse;
(3)ItcanbeusedwithoutinterruptingthenetworkoperationAddorsetunder;
(4)Thereisnoneedtorepeatedlypurchaseservers,whichreducestheuser’spurchaseandmaintenancecosts.
Sharingadvantages
2.UserscansharealargeamountofCD-ROMdiscdataatharddiskspeedthroughthenetwork
(1)BecausethediscmirroringserverisThedatafilesintheCDaremirroredtotheharddiskoftheCDmirroringserver,andthenbrowsedbytheuserthroughthenetwork.Therefore,throughtheCDmirroringserver,theusercanobtaintheaccessspeedoftheharddisklevel.ThiscompletelychangedthespeedbottleneckofsharingCD-ROMdatathroughCD-ROMtower,CD-ROMlibraryorCD-ROMdriveontheserver.
(2)Duetotheincreasingcapacityofharddisksnowadays,throughtheopticaldiscmirroringserver,systemadministratorscaneasilymirroruptohundredsofCD-ROMdiscstothelocalharddrive.middle.
(3)Asnetworkusersaccessthedataintheharddiskoftheopticaldiskmirroringserver,aslongasthenetworkqualityisguaranteed,itcanbeensuredthatdozenstohundredsofuserscanbrowseatthesametimeandwithhighqualityCD-ROMdata.
Uniquetechnology
VirtualCdromLibraryeLake®VCLiscalledVirtualCdromLibrary(VirtualCdromLibrary),whichisanupgradedversionoftheCD-ROMimageserverontheattachednetwork.InadditiontomaintainingtheadvantagesofordinaryopticaldiskmirroringserverssuchasnetworkstorageandsharingCD-ROMopticaldiskdataataharddiskspeed,thevirtualopticaldisklibraryalsocreativelyaddsthefollowingeLakeuniquetechnologies:
1,UserresponsetimeisshortTheexistingopticaldiskmirroringservergenerallyadoptstheSMB/CIFSnetworkprotocolintermsofopticaldisksharing.ThisprotocolwasformulatedbyMicrosoftandIntelin1987andisaclient/serverprotocol.Theclientcanaccessthesharedfilesystem,printerandotherresourcesontheserverthroughthisprotocol.ItusestheApplicationProgramInterface(API)ofNetBIOS.Inaddition,itisanopenprotocol,allowingprotocolexpansion-makingitlargerandmorecomplex;thereareabout65top-leveljobs,andeachjobhasmorethan120functions.ThestrongfunctionofSMB/CIFSnetworkprotocolisitsadvantage,butitisalsoitsdisadvantagefordiscsharing,becausethecomplexityofthefunctionwillreducetheefficiency,especiallywhentheaccessisjuststarted,itwillcausetheusertoconnecttotheserver.Ittakesalongtime.Ontheotherhand,mostofthefunctionsoftheSMB/CIFSnetworkprotocolarenotnecessaryinourCDsharing.Therefore,inviewofthecharacteristicsofCDaccess,wecustomizeaCDstreamwithspecificfunctions,shortuserresponsetime,andhightransmissionefficiency.Protocol,whichgreatlyimprovestheuser-friendlinessofdiscsharing.
2.SupportsremoteCDsharing.TheSMB/CIFSnetworkprotocolissuitableforuseinalocalareanetwork.ItdoesnotsupportremoteaccessontheInternet,whichgreatlylimitsthesharingofCDresources.Today,withtherapiddevelopmentoftheInternet,NotsupportingInternetremoteaccessisdifficultforuserstoaccept.UsingacustomTCP-basednetworkdiscstreamingprotocol,aslongastheserverisconnectedtotheInternet,anycomputerontheInternetcanaccesstheserver,andthereisnogeographicalrestrictionatall.
3.PowerfulvirtualCD-ROMdrivefunctionInordertofacilitateuserstoaccesstheserver'sCD-ROMresources,virtualizationtechnologyisadoptedtovirtualizeoneormoreCD-ROMdrivesontheclientside,sothattheuserusestheCD-ROMontheserverasifusingthelocalThesameastheCD.Therearesomespecialopticaldiscs,whichcanonlybeusedonthelocalphysicalopticaldrive,whichmakesitimpossibletousethepreviousopticaldiscmirroringserver.Byadoptingvirtualizationtechnology,wecanfullysupporttheseopticaldiscs.Atthesametime,weprovideafriendlyinterfaceCDclientprogram,usingthisclientprogram,userscanbrowsetheCDinformationontheserver,andcanviewthecurrentuserstatusinformation.SupportCD-ROMscripts,youcancomposerelatedCD-ROMsintoaCD-ROMscriptforone-timeuse,whichprovidesconveniencefortheuseofmanyCD-ROMdatabases.
4.DistributedstorageWiththefurtherpopularizationofcomputernetworks,variousCD-ROMdiscmaterialswillincreasesharply.Therefore,manyusershaveputforwardveryhighrequirementsfortheexpansionofthecapacityoftheopticaldiskmirroringserver.Inadditiontotheusualmethodofincreasingtheharddiskcapacityoftheopticaldiskmirroringserver,theeLake®VCLvirtualopticaldisklibraryalsohasauniquedistributedfunction-thatis,multipleeLake®VCLcanbeinstalledinthesamenetwork,throughtheclient'sWiththevirtualCD-ROMdrive,userscanaccessmultipleVCLserversonthenetworkatthesametime,andtherearenogeographicalrestrictionsbetweentheseservers.AslongastheVCLservershaveindependentInternetIPs,theycanbedistributedanywhereontheInternet.Thefunctionofdistributedstoragecanfacilitatetheonlineexpansionofthesystem,thusformingaclusterofopticaldiscmirroringservers.
5.Hierarchicaldiscmanagement.Manydiscimagesareplacedontheharddisk.Obscuredisclabelsaredifficulttoremember.Discretrievalhasbecomeaheadache.eLake®VCLserverprovidesyouwithWiththethoughtfulmulti-levelCDcatalogmanagementfunction,youcanorganizeandmanagecatalogsasyoulike.Goodcatalogmanagementmakesretrievalmoreconvenient.
6.UploadingCD-ROMfilesontheInternetWiththeexponentialgrowthofCD-ROMresourcesontheInternet,networkCD-ROMimagefileswillbecomeanimportantCD-ROMresourceforeLake®VCLservers.InordertomakegooduseofnetworkCDresources,eLake®VCLserversupportsnetworkCDuploadfunction,itcanquicklyuploadCDresourcesonthenetworktoeLake®VCLserver,andcanautomaticallyextractCDinformation,reallydoWorry-freedatasharing.
7.Thepowerfuldiscmirroringfunctionsupportsdatadiscs,VCDdiscs,DVDdiscsandAudioCDdiscsonthebasisofdifferentstrategiesformirroringthediscsectors.Accordingtotheadministrator’ssettings,notonlyItcanmirrorthedataofthedisc,andcanmirrorthephysicalinformationofthediscsuchasthevalidationandsub-channelsonthedisc,whichcanrealizethedisccloningfunctioninafullsense.
8.TheconvenientbillingfunctionusestheSMB/CIFSnetworkprotocol,whichmakesitdifficulttoimplementbillingservicesfordiscaccess.Itadoptsacustomopticaldiscstreamingprotocol,whichiscompletelydesignedfordiscsharing.Accordingtoneeds,theadministratorcansetthebillingfunctionforuserstoaccesstheserver.Itsupportsdifferentbillingstandardsaccordingtodifferentusers;considerthedifferentcostsofdifferentdiscs,Italsosupportsdifferentbillingstandardsfordifferentdiscs.
9.PowerfulusercontrolfunctionInordertoreasonablyallocateserverresourcesandensurethequalityofserviceofuserswhoareusingit,acertainlimitmustbeplacedonthenumberofusersservingatthesametime.Ontheotherhand,inordertosupportasmanysimultaneousaccessusersaspossible,itisnecessarytolimitthenumberofconcurrentaccessflowsfortheuserscurrentlyinuse,andlimittheflowofeachaccessflow,sothatbalancedaccesscanbeachieved.Streamingservicescanalsopreventmalicioususersfromattackingtheserverthroughlargetrafficaccess.BecauseofthedifferentnatureofCDresources,theremaybesomeCDmaterialsthataremoreimportantandonlyallowinternaluserstoaccess,whilesomeCDscanbeaccessedbyallusersontheInternet.Inordertomeettheneedsofadministrators,ourcustomizeddiscstreamingprotocolsupportstherestrictionofdifferentdiscstodifferentusers'accessrights.Becauseserverresourcesarethemostprecious,forthoseuserswhooccupyserverresourcesanddonotusethem,atimingdetectionmechanismisused.Whenuserswhohavenotaccessedtheserverforacertainperiodoftimearefound,theserverresourcesallocatedbyhimarereleasedandallocatedtootherusers.Whenhevisitstheserveragain,hewillbeallocatednewresourcesagain.Adoptingthiskindofdynamicresourceallocationstrategycanbetterutilizetheresourcesoftheserverreasonably.
10.Two-levelCacheperformanceimprovementstructureInordertoimprovetheperformanceoftheentireserver,atwo-levelCachesolutionisadoptedtoestablishanadaptiveCacheontheclientside,andtheprefetchmechanismisusedtoimprovenetworkdatatransmissionefficiency,Wheretheprefetchingisdonebyadedicatedthreadanddoesnotneedtobetriggeredbytheoperatingsystem.Atthesametime,alargeCacheisalsoestablishedontheserversidetoimprovethespeedoftheserverreadingdatafromtheopticaldiskimagefile.
Specifications
1)10/100MbpsautomaticdetectionEthernetinterface
2)Supportupto8ATA66interfaces
3)DistributionTypestorage,supportdynamicexpansionofmultiplediscmirroringservers
4)SupportCD-ROM,AudioCD,VCD,DVDandotherdiscformatsatthesametime
5)SupportmirroringasISO,BIN,MDFandotheropticaldiscimagefileformats.
6)Thespeedofmirroringa650MBdatadiscdoesnotexceed4minutes,andthespeedofmirroringa650MBVCDdiscdoesnotexceed6minutes.
7)100MbpsnetworkuploadCDimagefilerateis8MB.
8)DiscsharingadoptsacustomizeddiscstreamingprotocolbasedonTCPprotocol.
9)TheservermanagementdirectlyadoptstheTCPprotocol.
10)Support100userstoaccessatthesametime.
11)Support800accessdatastreamsatthesametime.
12)SupportsVCDstreamsplayedby48usersatthesametime.
13)Supportupto7disks.
14)Itcanhold1,900650MBdiscs.
15)Theclientsupports25virtualopticaldrives.
16)Theclientsupportssimultaneousaccessto25virtualopticaldisclibraryservers.
17)TheclientsupportsWindows98,Windows2000,WindowsXP.
DisadvantagesofCD-ROMlibrary
CD-ROMJukeboxisaCD-ROMnetworksharingdevicewithanautomaticdiskchangingmechanism(manipulator).Theopticaldisclibraryisgenerallyequippedwith1~6CD-ROMdrives,whichcanhold100~600CD-ROMdiscs.WhentheuseraccessestheCD-ROMlibrary,theautomaticdiskchangemechanismfirsttakesouttheCD-ROMfromtheCD-ROMdriveandplacesitinthedesignatedpositiononthediskrack,andthentakesouttherequiredCD-ROMdiskfromthediskrackandsendsitintotheCD-ROMdrivemiddle.Sincethediscchangingtimeoftheautomaticdiscchangingmechanismisusuallyontheorderofseconds,theaccessspeedoftheopticaldisclibraryisrelativelylow.
VirtualDiscLibrary
Overview
ThedisclibraryisactuallyakindofdiscthatcanstoredozensorhundredsofdiscswitharoboticarmandadiscThedisccabinetofthedrive.Theopticaldisclibraryisalsocalledanautomaticdiscchanger.Itusesamanipulatortoselectanopticaldiscfromthecabinetandsendittothedriveforreadingandwriting.Itslibrarycapacityisextremelylarge.DozensorevenhundredsofCDscanbeplacedinthecabinet.Thiskindofequipmentwithhugeonlinecapacityisverysuitableforinformationretrievalcenterssuchaslibraries,especiallyinteractiveCDsystemsanddigitalbooks.Librarysystem,real-timedatafilecentersystem,karaokeautomaticon-demandsystem,etc.Thecharacteristicsoftheopticaldisclibraryare:simpleinstallation,convenientuse,andsupportsalmostallcommonnetworkoperatingsystemsandvariouscommoncommunicationprotocols.AstheopticaldisclibrarygenerallyusesastandardEIDEopticaldrive(orastandard5-piecediscchanger),itisveryeasytomaintain,replaceandmanage,andatthesametimereducethecostandprice.Andbecausetheopticaldisclibrarygenerallyhasbuilt-inintelligentcomponentssuchashigh-performanceprocessors,high-speedcaches,fastflashmemory,dynamicaccessmemory,networkcontrollers,etc.,ithasstrongerinformationprocessingcapabilities.
DevelopmentHistory
Intheearly1990s,CD-ROMhasbeenwidelyused.AlthoughthepriceofCD-ROMdiscsisnothigh(tensofdollars),thepriceofCD-ROMdrivesisquiteexpensive,withapriceofmorethan1,000dollars.InordertoenablemultiplepeopletosharecheapCD-ROMdiscsonthenetwork,peoplewereinspiredbytheJukeboxinthebaranddevelopedadisclibrary,sothedisclibraryisusuallycalledJukebox.FromCDdisclibrarytoDVDdisclibrary,theexistenceofdisclibraryhasahistoryof10years.Inthepast,duetothesmallstoragecapacity,highprice,anddifficultyinmakingmechanicalpartsofopticaldiscs,ithasnotbeenpopularizedinthepast.However,inrecentyears,duetothegreatlyincreasedstoragecapacityofsingleopticaldiscs,opticaldisclibrariesarecomparedwithcommonstoragedevicessuchasdiskarrays.,Tapelibraryandotherpriceperformanceadvantagesarebecomingmoreandmoreobvious.Asastoragedevice,theopticaldisclibraryhasgraduallybeenusedinvariousfields,suchasbankbillimagestorage,insuranceagencydatastorage,andallotherlarge-capacitynear-linedatastorageoccasions.
Currentstatus
ThemorecommonopticaldisclibrariesonthemarketmainlyincludeDISC-BD(Blu-rayDiscLibrary)andDISC-C(UDO2DiscLibrary)producedbyDISCGmbH,aprofessionaldisclibrarymanufacturer.AndDVDdisclibraryproducedbyHewlett-PackardandJVC.ThereisnodoubtthattheBlu-rayDisclibrarytechnologyhasmaturedandwillbecomearapidlyemergingnewarmyinthestoragefield.LetustakeacloserlookattheBlu-rayDiscLibrary.
Workingprinciple
TheinternalstructureoftheBlu-rayDiscLibrary(BDJukebox)isasfollows.
Theopticaldisclibraryisakindofopticaldiscnetworksharingequipmentwithanautomaticdiscchangingmechanism(manipulator).Theopticaldisclibrarygenerallyconsistsofthreeparts:theopticaldiscrackforplacingtheopticaldisc,theautomaticdiscchangingmechanism(manipulator)andthedrive.Theopticaldisclibraryisgenerallyconfiguredwith1to14drives,whichcanbearead-onlyBlu-raydrive,aBlu-rayburner,oraDVDdrive,whichcanhold45to690discs,andeachdisccompartmentcanhold15or50discs.Itisdividedintointelligenthot-swappablediskstorageandordinarystorage.Thisistofacilitatethestorageandaccessofopticaldisks,andtheotheristodirectlyformthenear-lineandofflinecollocationstructureofthetertiarystorage.Theopticallibraryisconnectedtothenetworkserverthroughahigh-speedSCSIport,andtheopticaldiscdriveexchangesdatawiththehostthroughitsowninterface.Whentheuseraccessestheopticaldisclibrary,theautomaticdiscchangingmechanismfirsttakesouttheopticaldiscinthedriveandplacesitinadesignatedpositiononthediscrack,andthentakesouttherequireddiscfromthediscrackandsendsitintothedrive.Thechangingtimeoftheautomaticchangingmechanism(manipulator)isusuallyontheorderofseconds.
FeaturesofBlu-ray
Asalarge-capacityopticalstoragedevice,Blu-rayDiscLibraryhasthefollowingcharacteristics:
1.Productserialization:Blu-rayDiscLibraryhasbeenHaveBD-ROMandBD-RElibraries.
2.Highcapacity:thecapacityofeachdisccanreach50GB,andthetotalcapacityofthedisclibrarycanreachupto35TB;
3.Highreliability:thelifeofthediscis100year.
4.Storagemediumwithhighperformance/priceratio:theaccessspeedoftheopticaldiscisalmostclosetothespeedoftheharddisk,andthereplaceableintelligenthot-swappableopticaldiscstoragecanmakethecapacityoftheopticaldisclibraryreachinfinite,atthesametime,Youcanchoosemultipledrivesandusedualdisktransfertoimproveaccessperformance;
5.Flexibledesign:Thereareavarietyofmodelstochoosefrom,and,asyourneedsgrow,youcanExpandstoragecapacity.Opticaldrivescanbeadded,andperformancecanbeimprovedbyincreasingthe"datavolumeundertheread/writehead".
6.Seamlessconnectionwithvarioussystems:itcanbeappliedtoWindowsNT,NetWare,Unix,HP,IBMAIX,SUNOS.
7.Easytoinstall:connectdirectlytotheserver,SCSIinterface.
8.Easytouse:theclientdoesnotneedtoinstallanysoftwareandcanbeaccesseddirectly.
9.Easytomanage:Justsimpletrainingandmanagementautomation.
10.Highreliability:Theaveragetimebetweenfailuresis5milliontimes.
11.Lowenvironmentalrequirements:fullyenclosedcabinet,internalself-purificationandfilterablesystem.
12.Fastretrievalspeed:supportscross-diskretrieval.
Purpose
Blu-raydisclibrary,suitableforalllarge-capacitydatastorageoccasions,suitableforstoringsomedatathatisnotfrequentlychanged,suchas:hospitalmedicalimagingdata,Importantbillimagematerialsoffinancialinstitutionssuchasbanks,librarybookstores,TVstations'audio-visualdatabases,andsoon.
Blu-raydisclibraryisalsosuitableasasecondarystoragedevice.Thetraditionalmethodhasalwaysbuiltdataordatabasesontheharddisk,butaccordingtothestatisticsofforeignauthoritativeorganizations,80%oftheharddiskdataisinfrequentlyaccessed,buttheseinfrequentlyaccesseddataoccupypreciousandexpensivediskspace.WiththeDVDdisclibrary,youcanstorefrequentlyaccesseddataondisksordiskarrays,andinfrequentlyaccesseddatainthesuper-capacityDVDdisclibrary,therebyobtainingatotalstoragecapacityofhundredsofTB,butatacostThepriceisonly10%to20%ofthesamecapacitydisk.
Thesecondarystoragesystemsolutionnotonlysupportstraditionalfiles,butalsosupportsvarioustypesofdatabases,suchasOracle,Informix,SQL,etc.TheusercandirectlybuildthetablespaceofthedatabaseintheCD-ROMlibrary.OnBlu-rayorDVD-RAMdiscs,dataqueryanddatainsertion,modification,anddeletionoperationscanbesupported.Itiscompletelytransparenttousersandfeelsasconvenientasusingaharddisk.;
Formanyuserswithlargedatavolume,theyusuallybackuphistoricaldatatotapeandrestoreittotheharddiskonceneeded.Thisisverytroublesomeandwilltakealotoftime.ButiftheseHistoricaldataoccupiesvaluablediskspaceforalongtime,whichisunacceptable.Therefore,thehistoricaldataofthedatabasecanbemigratedtotheopticaldisclibrary,sothatusershavehugedataspace,lowprice,andeaseofonlinestorage.;
Development
Asastoragemediumthathasonlyemergedinthepasttenyears,opticaldiskshaveuniqueadvantagescomparedwithtraditionalmagnetictapesandfloppydisks.Tapesareespeciallydatastreams.Thesingle-diskcapacityofthetapeisindeedlarge,reaching500GB,butthepriceofsuchatapeisnearly1,000USdollars.Atthesametime,ifthetapeisnotwellstored,itiseasytomoldandwear,anditiseasytolosedatawhenitisclosetothemagnet.Moreover,tapedrivesofdifferentformatsarenotCompatible,causinginconvenienceinmediadataexchange.Duetothesmallcapacityoffloppydisks,evenZipfloppydiskshaveacapacityofonly120M,andtheirsafetyandreliabilityarepoor,sotheyarerarelyused.IfthestoragetimeofMOdiscsistoolong,ithasbeenproventhatdatamaybelost,anditisnotrecommendedintheindustry.However,duetothelargecapacityofBlu-rayDiscs,thecurrentcapacityofasinglediscis50GB,andthecapacitywillquicklyexceed200GBinthefuture.Itiseasytosave,withashelflifeofmorethan50years,andhighreliability.Evenifthesurfaceisworn,itcanbequicklyrepairedwitharepairmachineofseveralhundredyuan.,Easytocarry,easytoexchangedata,mostofeachPCcurrentlyhasaCD-ROMdriveinstalled.Inparticular,Blu-ray,asanewstoragemediumtrendingintheworld,willhaveunlimitedprospects.Itcanbeusedasanormalbackupmediumaswellasareal-timestoragecarrier.Comparedwithharddisks,opticaldisksalsohavemanyincomparableadvantages.Harddisksarerelativelyfragile,andareeasilydamagedwhenencounteringlargevibrationsandshocks.Opticaldiskscansolvetheseproblemswell.
ThefollowingisacomparisonofDVDdiscsandtraditionaltapemedia:comparisonofopticaldiscsanddatastreamtapes
Opticaldatastreamtapes
Retentionperiod30-100years3-8years
Theservicelifeisnon-contact,rewritable100000times,andthecontactisabout100times.
ReadingmethodRandomreadingsequentialreading
ReadingFetchingfrequency
Capacity50G100G/disk
Readingspeed2.5-10MB/S2.5-10MB/S
Storageenvironmentrequirements
Dust-proof,normalroomtemperatureandconstanttemperature,constanthumidity,dust-proof,insect-proof,mildew-proof,fire-proof,waterproof,anti-magnetic,andanti-glare.Thesafetyoftheresidencewillnotcauseanylossinadditiontofireandmaliciousdamage,andthesafetyisveryhigh.
Thetapeisveryfragile,andtherewillbeunrecoverablelossesifyouarenotcareful,andthesecurityisverylow.
Maintenancecostisbasicallynomaintenancecost.Regularreplacementoftapes
EachTBconsumes37degreesofelectricityperyear(thelargestmodelofopticaldisclibrary).Unknown,butpreliminaryestimatesareatleast5-10oftheopticaldisclibraryTimes
CompatibilityisfullycompatiblewithDVD,CD
Performanceandapplicationcomparison
Currentlywidelyusedstoragedevicesincludediskarrays,opticaldisclibraries,opticaldiscmirroringservers,etc..Nowmakeabriefcomparisonoftheseproducts.
Diskarraysandopticaldiskmirroringserversarebothharddisk-basedstoragedevices.Theadvantageisthattheaccessspeedisfastandthenumberofconcurrentrequeststhatcanbesupportedislarge;thedisadvantageisthatthecapacityisrelativelysmall.Ifyouwanttoreachthecapacityoftheopticaldisklibrary,Thenthepriceoftheharddiskwillbeastronomical,thedamageprobabilityoftheharddiskishigh,andtheanti-vibrationabilityispoor.Whenyouwanttoexchangedata,youmustuseothermediaforbackupbeforeitiseasytocarry.Thedataiseasytobetamperedwith.5years.Thedisadvantageoftheopticaldisclibraryisthattheconcurrentresponseabilityisnotasgoodasthatofthediskarray,buttheadvantagesarealsoobvious:largecapacityandeasytoexpand,lowpriceandeasytopromote,andhighsecurityofthediscmedium(Blu-rayorCD-RorDVD-RdiscafterburningCannotberewritten),thestorageperiodofthedisccanbeaslongasonehundredyears,itismold-proofandmoth-proof,anditisveryconvenienttocarry.Ifthenumberofbuilt-indrivesinthelibraryincreases,andahigh-speedcacheisestablishedontheexternaldisk,theresponsecapabilityoftheopticaldisclibrarycanalsoreachhighLevel,andatthesametime,itisquiteeasytomakeCDs.