I-hard drive yokuqala yehlabathi, i-IBM RAMAC 305, eyakhululwa ngo-1956, iqulethe i-5 MB yedatha kuphela, kwaye inobunzima be-970 kg kwaye yafaniswa ngobukhulu nefriji yoshishino. Iiflegi zamashishini zanamhlanje zinokuqhayisa ngomthamo osele ukwi-20 TB. Khawufane ucinge: iminyaka eyi-64 edlulileyo, ukuze urekhode le mali yolwazi, bekuya kuthatha ngaphezu kwe-4 yezigidi ze-RAMAC 305, kunye nobukhulu beziko ledatha elifunekayo ukuba libaphathe, liza kudlula iikhilomitha ezili-9, ngelixa namhlanje incinci. ibhokisi enobunzima obumalunga nama-700 grams! Ngeendlela ezininzi, oku kwanda okumangalisayo kobuninzi bokugcina kuye kwaphunyezwa ngenxa yokuphuculwa kweendlela zokurekhoda ngemagnethi.
Kunzima ukukholelwa, kodwa ngokusisiseko uyilo lwe-hard drives aluzange lutshintshe phantse iminyaka engama-40, ukususela ngo-1983: kwakungelo xesha apho i-3,5-intshi yokuqala ye-hard drive RO351, eyaphuhliswa yinkampani yaseScotland i-Rodime, yabona ukukhanya. Lo mntwana wafumana iipleyiti zemagneti ezimbini ze-10 MB nganye, oko kukuthi, wayekwazi ukubamba idatha ephindwe kabini njengoko ihlaziywa i-412-intshi ST-5,25, ekhutshwe yi-Seagate ngonyaka omnye kwi-IBM 5160 iikhomputha zomntu.
Rodime RO351 - yokuqala yehlabathi 3,5-intshi hard drive
Nangona i-innovativeness kunye nobukhulu be-compact, ngexesha lokukhululwa kwe-RO351, phantse akukho mntu wayeyidinga, kwaye zonke ezinye iinzame zikaRodime zokufumana indawo kwimarike ye-hard drive zahluleka, yiyo loo nto inkampani yanyanzeleka ukuba iyeke ukusebenza. ngo-1991, emva kokuba uthengise phantse zonke ii-asethi ezikhoyo kunye nokunciphisa urhulumente ukuya ubuncinane. Nangona kunjalo, u-Rodime wayengahloselwe ukuba angabikho: kungekudala abenzi abakhulu be-hard drive baqala ukuphendukela kuye, befuna ukufumana ilayisenisi yokusebenzisa ifom ye-patent ye-Scots. I-3,5" ngoku ikumgangatho weshishini kubo bobabini abathengi kunye nee-HDD zeshishini.
Ngokufika kwamanethiwekhi e-neural, i-Deep Learning kunye ne-Intanethi yeZinto (IoT), umthamo wedatha eyenziwe ngabantu sele iqalile ukukhula njenge-avalanche. Ngokutsho koqikelelo lwe-IDC ye-arhente yokuhlalutya, ngo-2025 inani lolwazi olwenziwe ngabantu bobabini ngokwabo kunye nezixhobo ezisijikelezileyo ziya kufikelela kwi-175 zettabytes (1 Zbyte = 1021 bytes), kwaye oku nangona ukuba kwi-2019 yayingu-45. I-Zbytes, kwi-2016 - i-16 Zbytes, kwaye emva kwe-2006, inani elipheleleyo ledatha eveliswa kuyo yonke imbali ebonakalayo ayizange idlule i-0,16 (!) Zbytes. Ubuchwephesha banamhlanje bunceda ukujamelana nokuqhuma kolwazi, phakathi kwazo iindlela eziphuculweyo zokurekhoda kwedatha azikho zokugqibela.
LMR, PMR, CMR kunye ne-TDMR: yintoni umahluko?
Umgaqo wokusebenza kwee-hard drives ulula kakhulu. Iipleyiti zentsimbi ezibhityileyo eziqatywe ngomaleko wemathiriyeli ye-ferromagnetic (into eyikristale enokuhlala imagnetic kwanaxa ingekho imagnethi yangaphandle kwiqondo lobushushu elingaphantsi kweCurie point) zihamba ngokunxulumene nebhloko yokurekhoda kweentloko ngesantya esiphezulu (5400 rpm okanye Kaninzi). Xa umbane wombane usetyenziswa kwintloko yokubhala, kuvela intsimi yamagnetic etshintshanayo, etshintsha indlela ye-magnetization vector ye-domains (discrete regions of matter) ye-ferromagnet. Ukufundwa kwedatha kwenzeka nokuba kungenxa yesenzeko sokungeniswa kwe-electromagnetic (ukuhamba kwemimandla enxulumene nenzwa kubangele ukwenzeka kombane otshintshayo wangoku ekugqibeleni), okanye ngenxa yempembelelo enkulu yemagnetoresistive (ukuxhathisa kombane kwesivamvo kuyatshintsha phantsi impembelelo yemagnethi), njengoko iphunyezwa kwizixhobo zokugcina zale mihla. Idomeyini nganye ifaka iikhowudi intwana enye yolwazi, ithatha ixabiso eliqiqileyo "0" okanye "1" ngokuxhomekeke kwicala le vector yemagnetization.
Ixesha elide, ii-hard drives zasebenzisa indlela ye-Longitudinal Magnetic Recording (LMR), apho i-domain magnetization vector yalala kwi-plane ye-platter magnetic. Ngaphandle kokulula kokuphunyezwa, obu buchwepheshe bune-drawback ebalulekileyo: ukuze woyise ukunyanzeliswa (utshintsho lwamasuntswana omagnetic ukuya kwindawo enendawo enye), indawo enomtsalane yebuffer (ebizwa ngokuba yindawo yokulinda) kwafuneka ishiywe phakathi. iingoma. Ngenxa yoko, ubuninzi bokurekhoda obuninzi obufunyenwe ekupheleni kobu buchwepheshe be-150 Gb / in2 kuphela.
Ngo-2010, i-LMR yaphantse yatshintshwa yi-PMR (Perpendicular Magnetic Recording - perpendicular magnetic recording). Umahluko omkhulu wale teknoloji ukusuka ekurekhodweni kwamagnetic longitudinal kukuba i-magnetic directivity vector ye-domain nganye ifumaneka kwi-angle ye-90 Β° ukuya kumphezulu weplate yamagnetic, okwenza kube lula ukunciphisa i-gap phakathi kweengoma.
Ngenxa yoku, ukuxinwa kokurekhoda kwedatha kuye kwanda kakhulu (ukuya kuthi ga kwi-1 Tbit / inch2 kwizixhobo zanamhlanje), ngelixa kungancami iimpawu zesantya kunye nokuthembeka kwee-hard drives. Okwangoku, ukurekhodwa kwemagnethi ye-perpendicular yeyona nto iphambili kwintengiso, yiyo loo nto ikwabizwa ngokuba yiCMR (Ukurekhodwa kweMagnetic okuQhelekileyo - ukurekhodwa kwemagnethi eqhelekileyo). Kwangaxeshanye, umntu kufuneka aqonde ukuba akukho mahluko kwaphela phakathi kwe-PMR kunye neCMR - le yinguqulelo nje eyahlukileyo yegama.
Xa ujonge kwiinkcukacha zeehard drives zangoku, usenokudibana nesishunqulelo esifihlileyo se-TDMR. Ngokukodwa, le teknoloji isetyenziswa ngamashishini aqhuba iiklasi . Ukusuka kwimbono yefiziksi, i-TDMR (emele ukuRekhodwa kweMagnetic eDimensional-dimensional-dimensional magnetic recording) ayahlukanga kwi-PMR eqhelekileyo: njengangaphambili, sijongene neengoma ezingaphambanisiyo, imimandla apho i-oriented perpendicular. kwinqwelomoya yamacwecwe kazibuthe. Umahluko phakathi kwetekhnoloji ilele kwindlela yokufunda ulwazi.
Kwibhloko yeentloko zemagnethi zee-hard drives ezenziwe kusetyenziswa itekhnoloji ye-TDMR, intloko nganye yokurekhoda inezinzwa ezimbini zokufunda ezithi ngaxeshanye zifunde idatha kwingoma nganye egqithisiweyo. Oku kuphelelwa kuvumela umlawuli we-HDD ukuba ahluze ngokufanelekileyo ingxolo ye-electromagnetic ebangelwa yi-Intertrack Interference (ITI).
Ukusombulula ingxaki nge-ITI kubonelela ngeenzuzo ezimbini ezibaluleke kakhulu:
- ukuncitshiswa kwengxolo yengxolo ivumela ukwandisa ubuninzi bokurekhoda ngokunciphisa umgama phakathi kwamathrekhi, ukubonelela ngokuzumayo kwinani elipheleleyo ukuya kwi-10% xa kuthelekiswa ne-PMR eqhelekileyo;
- Idityaniswe ne-RVS iteknoloji kunye ne-actuator ye-micro-position emithathu, i-TDMR ixhathisa ngokufanelekileyo ukungcangcazela okujikelezayo okubangelwa yi-hard drives, inceda ukufezekisa amanqanaba angaguqukiyo okusebenza nakwezona ndawo zifuna kakhulu.
Yintoni i-SMR kwaye ityiwa ngantoni?
Imilinganiselo yentloko yokubhala malunga namaxesha angama-1,7 amakhulu kunemilinganiselo yenzwa efundwayo. Umahluko ochukumisayo onjalo uchazwa ngokulula: ukuba imodyuli yokurekhoda yenziwe nokuba incinci ngakumbi, amandla omhlaba wemagnethi enokuvelisa awayi kukwanela ukwenza imagnethi imimandla yomaleko weferromagnetic, okuthetha ukuba idatha ayinakukwazi ukuyikhupha. zigcinwe. Kwimeko yenzwa yokufunda, le ngxaki ayiveli. Ngaphezu koko, i-miniaturization yayo yenza ukuba kube lula ukunciphisa impembelelo ye-ITI ekhankanywe ngasentla kwinkqubo yokufunda ulwazi.
Le nyaniso yenza isiseko sokurekhodwa kweethayile kwimagnethi (Shingled Magnetic Recording, SMR). Masiqonde ukuba isebenza njani. Xa usebenzisa i-PMR yendabuko, intloko yokubhala ihamba ngokumalunga nomzila ngamnye wangaphambili ngomgama olingana nobubanzi bayo + ububanzi bendawo yokukhusela (indawo yokugada).
Xa usebenzisa indlela yethayile yokurekhoda kwamagnetic, intloko yokurekhoda iqhubela phambili kuphela inxalenye yobubanzi bayo, ngoko ke umkhondo ngamnye wangaphambili ubhalwe ngokuyinxenye ngokulandelayo: iingoma zemagneti ziwelana njengeethayile zophahla. Le ndlela yenza ukuba kube lula ukwandisa ubuninzi bokurekhoda, ukubonelela ngenzuzo yomthamo ukuya kwi-10%, ngelixa lingachaphazeli inkqubo yokufunda. Umzekelo ngulo β I-3.5-intshi yokuqala yehlabathi ye-20 TB drives kunye ne-SATA / SAS interface, ukubonakala kwayo okwenziwe ngokubonga kwi-teknoloji entsha yokurekhoda. Ngaloo ndlela, ukutshintshela kwiidiski ze-SMR kukuvumela ukuba ukwandise ubuninzi bokugcinwa kwedatha kwii-racks ezifanayo kwiindleko ezincinci zokuphucula i-IT.
Ngaphandle kwenzuzo ebaluleke kangaka, i-SMR inesiphene esicacileyo. Ekubeni iingoma zemagnethi ziwelana, xa uhlaziywa idatha, kuya kufuneka ukuba ubhale kwakhona kungekuphela nje isiqwenga esifunekayo, kodwa kunye nazo zonke iingoma ezilandelayo ngaphakathi kweplate yamagnetic, umthamo wayo unokudlula i-2 terabytes, egcwele ukuhla okukhulu. ekusebenzeni.
Ukudibanisa inani elithile leengoma zibe ngamaqela ahlukeneyo abizwa ngokuba ziizowuni kunceda ukusombulula le ngxaki. Nangona le ndlela yokugcinwa kwedatha inciphisa umthamo opheleleyo we-HDD (ekubeni izithuba ezaneleyo kufuneka zigcinwe phakathi kweendawo zokukhusela iingoma zokubhala ngaphezulu kumaqela angabamelwane), oku kunokukhawuleza ngokukhawuleza inkqubo yohlaziyo lwedatha, ekubeni ngoku kuphela inani eliqingqiweyo leengoma. thatha inxaxheba kuyo.
Ukurekhodwa kwemagnethi okufakwe kwithayile kubandakanya iindlela ezininzi zokuphumeza:
- Qhuba i-SMR elawulwayo (i-Drive elawulwa yi-SMR)
Inzuzo yayo ephambili kukuba akukho mfuneko yokuguqula isofthiwe kunye / okanye i-hardware ye-host host, ekubeni umlawuli we-HDD uthatha ulawulo lwenkqubo yokurekhoda idatha. Iidrives ezinjalo zinokudityaniswa kuyo nayiphi na inkqubo ene-interface efunekayo (i-SATA okanye i-SAS), emva koko i-drive iya kuba ngokukhawuleza ilungele ukusetyenziswa.
Ukungalungi kwale ndlela kukuguquguquka kokusebenza, okwenza i-Drive Managed SMR ingafaneleki kwizicelo zeshishini apho ukuhambelana kwenkqubo kubalulekile. Nangona kunjalo, iidiski ezinjalo zisebenza kakuhle kwiimeko ezivumela ixesha elaneleyo lokuchithwa kwedatha yangasemva ukuze kugqitywe. Ke, umzekelo, iidrive zeDMSMR Ilungiselelwe ukusetyenziswa kwi-8-bay encinci ye-NAS, lukhetho oluhle kakhulu logcino okanye inkqubo yogcino efuna ugcino lwexesha elide.
- I-SMR elawulwa ngumamkeli (i-SMR elawulwa ngumamkeli)
I-SMR elawulwa ngumamkeli yeyona nto ikhethwayo yokuphunyezwa kwethayile kusetyenziso lweshishini. Kulo mzekelo, inkqubo yenginginya ngokwayo inoxanduva lokulawula ukuhamba kwedatha kunye nokufunda / ukubhala imisebenzi, usebenzisa ezi njongo izandiso ze-ATA (Isixhobo esiZone i-ATA iSeti yomyalelo, i-ZAC) kunye ne-SCSI (iMiyalelo yeBlock yeZone, i-ZBC) ujongano oluphuhliswe ngu. iikomiti ze-INCITS T10 kunye ne-T13 .
Xa usebenzisa i-HMSMR, yonke indawo yokugcina ekhoyo ihlulwe ibe ziindidi ezimbini zemimandla: Imimandla eqhelekileyo (imimandla eqhelekileyo), esetyenziselwa ukugcina imethadatha kunye nokurekhoda okungaqondakaliyo (enyanisweni, dlala indima ye-cache), kunye neMimandla efunekayo yokuBhala ngokulandelelanayo. (imimandla yokubhala ngokulandelelana), ethatha indawo enkulu yomthamo opheleleyo wediski enzima, apho idatha irekhodwa ngokungqongqo ngokulandelelana. Idatha engacwangciswanga igcinwa kwindawo ye-cache, ukusuka apho ingagqithiselwa kwindawo ehambelanayo yokubhala ngokulandelelana. Ngenxa yoko, onke amacandelo omzimba abhalwe ngokulandelelana kwi-radial direction kwaye abhalwa kuphela emva kokugubungela, okukuvumela ukuba ufezekise ukusebenza kwenkqubo ezinzileyo kunye nokuqikelelwa. Kwangaxeshanye, ii-HMSMR ziqhuba zixhasa imiyalelo yokufunda engacwangciswanga efana nedrive esebenzisa i-PMR eqhelekileyo.
I-SMR eLawulwayo ngumamkeli iphunyezwe kwiihard drives zodidi lweshishini .
Umgca ubandakanya umthamo ophezulu we-SATA kunye ne-SAS drives eyenzelwe ukusetyenziswa kumaziko edatha ye-hyperscale. Inkxaso ye-SMR eLawulwayo ye-Host yandisa kakhulu ububanzi bee-hard drives ezinjalo: ukongeza kwiinkqubo zokulondoloza, zigqibelele ukugcinwa kwamafu, i-CDN okanye iiplatifomu zokusasaza. Umthamo ophezulu we-hard drives ikuvumela ukuba ukhulise kakhulu ubuninzi bogcino (kwii-rack ezifanayo) kunye neendleko ezincinci zokuphucula, kunye nokusetyenziswa kwamandla aphantsi (ngaphantsi kwe-0,29 watts nge-terabyte yolwazi olugciniweyo) kunye nokuchithwa kobushushu (kumndilili we-5 Β° C ngaphantsi kuno analogues) - ngakumbi ukunciphisa iindleko zokusebenza zokugcina iziko ledatha.
Ukungalungi kuphela kwe-HMSMR kubunzima bokuthelekisa ukuphunyezwa. Into kukuba namhlanje akukho nkqubo enye yokusebenza okanye isicelo sinokusebenza kunye needrives ezinjalo ngaphandle kwebhokisi, yingakho utshintsho olukhulu kwi-software stack lufuneka ukulungelelanisa isiseko se-IT. Okokuqala, oku kukhathazeka, ngokuqinisekileyo, i-OS ngokwayo, ephantsi kweemeko zamaziko edatha anamhlanje asebenzisa i-multi-core kunye ne-multi-socket servers ngumsebenzi ongenamsebenzi. Unokufunda ngakumbi malunga neenketho zokuphumeza inkxaso ye-Host Managed SMR kwisixhobo esikhethekileyo. enikezelwe kwimiba yokugcina idatha yendawo. Ulwazi oluqokelelweyo apha luya kukunceda ukuba uvavanye kwangaphambili ukulungela kwezibonelelo zakho ze-IT ukuze utshintshele kwiinkqubo zokugcinwa kwendawo.
- I-SMR ye-Host Aware (i-SMR ixhaswa ngumamkeli)
I-Host Aware SMR-enabled izixhobo zidibanisa ukulunga kunye nokuguquguquka kweDrive Managed SMR kunye nesantya esikhawulezayo sokurekhoda kwe-Host Managed SMR. Iidrives ezinjalo zibuyela ngasemva zihambelana neenkqubo zokugcina ilifa kwaye zinokusebenza ngaphandle kolawulo oluthe ngqo oluvela kumamkeli, kodwa kulo mzekelo, njengakwi-DMSMR drives, ukusebenza kwabo kuba yinto engalindelekanga.
Njengomsingathi oLawulwayo i-SMR, i-SMR yoMbumbi eQinisekisayo isebenzisa iindidi ezimbini zemimandla: iMimandla yeSiqhelo yokubhala ngokungacwangciswanga kunye neMimandla eKhethekileyo yokuBhala ngokulandelelanayo (imimandla ekhethwayo ukurekhoda ngokulandelelana). Le yokugqibela, ngokungafaniyo neMimandla efunekayo yokuBhala ngokulandelelanayo ekhankanywe ngasentla, idluliselwa ngokuzenzekelayo kuluhlu lwezinye eziqhelekileyo ukuba ziqala ukubhala idatha ngendlela engacwangciswanga.
Ukuphunyezwa komkhosi we-SMR kubonelela ngeendlela zangaphakathi zokubuyisela ekubhaleni okungahambelaniyo. Idatha engaqhelekanga ibhaliwe kwindawo ye-cache, ukusuka apho idiski inokudlulisa ulwazi kwindawo yokubhala ngokulandelelana emva kokuba zonke iibhloko eziyimfuneko zifunyenwe. I-drive isebenzisa itafile ye-indirection yokulawula i-inorder ibhala kunye nokuchithwa kwemvelaphi. Nangona kunjalo, ukuba intsebenzo eqikelelweyo nephuculweyo iyafuneka kwizicelo zeshishini, oku kusengaphunyezwa kuphela xa umamkeli ethatha ulawulo olupheleleyo lwalo lonke uhambo lwedatha kunye neendawo zokubhala.
umthombo: www.habr.com