I-RAID yisisombululo esasungulwa ekuqaleni kwemakethe yeseva yenethiwekhi njengendlela yokudala isitoreji esikhulu ngezindleko eziphansi. Ngokuyinhloko, kungathatha ama-driy hard drives amaningi futhi uwahlanganise ndawonye ngokusebenzisa isilawuli ukuze unikeze idrayivu eyodwa eyodwa enkulu. Yilokho okushiwo i-RAID: i-redundant ehlukahlukene yokushayela okungabizi noma ama-disks. Ukuze kufezeke lokhu, isofthiwe nezilawuli ezikhethekile kwakudingeka ukuphatha idatha yokwahlukana phakathi kokushayela okuhlukahlukene.
Ekugcineni, amandla okucubungula ohlelweni lwakho lwekhompyutha evamile avumela izici ukuhlunga indlela yazo emakethe yamakhompyutha .
Isitoreji se-RAID manje singase sibe isofthiwe noma i-hardware esekelwe , futhi ingasetshenziselwa izinhloso ezintathu ezihlukene. Lokhu kufaka phakathi amandla, ukuphepha, nokusebenza. Ikhono lilula elivame ukuhilela cishe zonke izinhlobo zokusetha kwe-RAID esetshenzisiwe. Isibonelo, amabhayisikili amabili anamandla angaxhunyaniswa ndawonye njengendlela yokushayela eyodwa ohlelweni lokusebenza ngokuphumelelayo ekwenzeni i-virtual drive ephindwe kabili amandla. Ukusebenza esinye isizathu esiyinhloko sokusebenzisa ukusetha kwe-RAID kumakhompuyutha. Esikhathini esifanayo isibonelo sokushayela okubili esisetshenziselwa ukushayela okukodwa, isilawuli singakwazi ukwehlukanisa i-data chunk zibe izingxenye ezimbili bese ubeka ngayinye yalezo zindawo ngodrayivu ohlukile. Lokhu kuphumelela kabili ukusebenza kokubhala noma ukufunda idatha kusistimu yokugcina. Okokugcina, i-RAID ingasetshenziselwa ukuphepha kwedatha.
Lokhu kwenziwa ngokusebenzisa ezinye isikhala kwimishini yokushayela ukuze iqoqe ngokucophelela idatha ebhaliwe kokubili kokushayela. Nalapha futhi, ngamashayela amabili singayenza ukuze idatha ibhalelwe kokubili ukushayela. Ngakho-ke, uma eyodwa idrayivu ihluleka, enye isenayo idatha.
Ngokuya ngezinhloso ze-storage array ofuna ukuyibeka ndawonye ohlelweni lwakho lwekhompyutha, uzosebenzisa elinye lamazinga ahlukahlukene we-RAID ukuze ufeze lezi zinhloso ezintathu.
Kulabo abasebenzisa izinkinobho ezinzima kwikhompyutheni yabo , ukusebenza cishe kuyoba yinkinga enkulu kunekhono. Ngakolunye uhlangothi, labo abasebenzisa isimo esiqinile sezimoto bazofuna indlela yokuthatha amashayela amancane futhi bawahlanganise ndawonye ukuze benze idrayivu eyodwa enkulu. Ngakho ake sibuke amazinga ahlukahlukene we-RAID angasetshenziswa ngekhompyutha yomuntu siqu.
RAID 0
Leli yizinga eliphansi kunazo zonke ze-RAID futhi empeleni alinikezi noma yiluphi uhlobo lokubuyiswa kwe-redundancy yingakho libhekiswe ezingeni le-0. Okuyisisekelo, i- RAID 0 ithatha izinkomba ezimbili noma ngaphezulu futhi uzibeka ndawonye ukuze zenze umthamo omkhulu wokukwazi ukuhamba. Lokhu kufezwa ngeprosesa ebizwa ngokuthi i-striping. Amabhuloki wedatha aphuliwe abe yimininingwane yedatha bese ebhalwe ngokulandelana kuwo wonke amashayela. Lokhu kunikeza ukusebenza okwenyuka ngoba idatha ingabhalwa ngesikhathi esisodwa kumshayela wesilawuli ngokuphumelelayo ukwandisa ijubane lezimoto. Ngezansi isibonelo sokuthi lokhu kungasebenza kanjani kuma-disks amathathu:
| Drayivu 1 | Drayivu 2 | Drayivu 3 | |
|---|---|---|---|
| Vimba 1 | 1 | 2 | 3 |
| Vimba 2 | 4 | 5 | 6 |
| Vimba 3 | 7 | 8 | 9 |
Ukuze i-RAID 0 isebenze ngokuphumelelayo ekuthuthukiseni ukusebenza kwesistimu, kuzomele uzame futhi uhambisane namashayela. I-drive ngayinye kufanele ibe nekhono elifanayo lokugcina isitoreji kanye nezici zokudlala.
Uma bengenjalo, khona-ke umthamo uzobe ukhawulelwe kumaningi omncane kunayo yonke yokushayela nokusebenza kuya kancane kunazo zonke zokushayela ngoba kufanele ulinde yonke imigqa ukuba ibhaliswe ngaphambi kokuthuthela kusethi esilandelayo. Kungenzeka ukuthi usebenzise amashayela angafani kodwa uma kunjalo, ukusetha kwe- JBOD kungase kuphumelele nakakhulu.
I-JBOD imele nje iqoqo lezinkomba futhi ngempumelelo nje iqoqo lezinkomba ezingafinyeleleka ngokuzimela komunye nomunye kodwa zibonakala njengesitoreji esisodwa esivumelelweni ohlelweni lokusebenza. Lokhu kuvame ukufezwa ngokuba ne-data span phakathi kokushayela. Ngokuvamile lokhu kubizwa ngokuthi yi-SPAN noma i-BIG.
Ngokuphumelelayo, ukusebenza kubona konke njengediski elilodwa kodwa amabhlokhi azobhalwa ngaphesheya kwe disk yokuqala aze agcwalise, bese uthuthukela okwesibini, okwesithathu, njll. Lokhu kuyasiza ekwengezeni umthamo owengeziwe ohlelweni lwekhompyutha olukhona futhi ngokushayela ngobukhulu obuhlukahlukene kodwa ngeke kwandise ukusebenza komshini wokushayela.
Inkinga enkulu nge-RAID 0 ne-JBOD setups ukuphepha kwedatha. Njengoba unezinkomba eziningi, amathuba okukhwabanisa kwedatha akhule ngoba unamaphuzu amaningi wokuhluleka . Uma ngabe yikuphi ukushayela ku-RAID 0 ukuhluleka kwehluleka, yonke idatha ayitholakali. Ku-JBOD, ukwehluleka kokushayela kuzoholela ekulahlekelweni kwanoma yiluphi ulwazi olwenzekile kulolo drayivu. Ngenxa yalokho, kungcono kulabo abafuna ukusebenzisa le ndlela yokugcina ukuze babe nezinye izindlela zokuvuselela idatha yabo.
RAID 1
Lelizinga lokuqala eliyiqiniso le-RAID njengoba linikeza izinga eligcwele lokubuyisela idatha egcinwe ohlwini. Lokhu kwenziwa ngenqubo ebizwa nge-mirroring. Ngokuphumelelayo, yonke idatha ebhaliwe ohlelweni ibhalwa ku-drive ngayinye ku-level 1 ihlu. Leli fomu le-RAID livame ukuqhutshwa nge-pair of drives njengoba ukwengeza amashayeli amaningi angeke angeze noma yimuphi umthamo owengeziwe, ukuphindwa okuningi. Ukuze kube ngcono ukunikeza isibonelo salokhu, nansi ishadi elibonisa ukuthi lizobhalwa kanjani kumashayeli amabili:
| Drayivu 1 | Drayivu 2 | |
|---|---|---|
| Vimba 1 | 1 | 1 |
| Vimba 2 | 2 | 2 |
| Vimba 3 | 3 | 3 |
Ukuze uthole ukusetshenziswa okuphumelela kakhulu kusuka kusetha ye-RAID 1, uhlelo luzophinde lusebentise amashayela afanayo afana nomthamo ofanayo nokulinganisa ukusebenza.
Uma kusetshenziselwa ukushayela okungahambisani kahle, khona-ke amandla okubala azolingana nokushayela komthamo omncane kunayo yonke. Ngokwesibonelo, uma i-terabyte eyodwa nesigamu kanye ne-terabyte drive eyodwa isetshenzisiwe ku-RAID 1, umthamo walolu hlelo luzoba yindawo eyodwa kuphela.
Leli phuzu le-RAID liphumelela kakhulu ekuvikelekeni kwedatha ngoba amashayela amabili asebenza ngokufanayo. Uma enye yamashayeli amabili ehluleka, enye inayo idatha ephelele yomunye. Inkinga ngalolu hlobo lokusetha ngokuvamile ngokunquma ukuthi yikuphi kokushayela kuhlulekile ngoba ngokuvamile isitoreji sitholakali uma omunye walaba ababili ehluleka futhi ngeke abuyele ngokufanele kuze kube yilapho kushayiswa idrayivu entsha endaweni yokuhluleka nokubuyiswa inqubo iyasebenza. Njengoba kushiwo ngaphambilini, akukho nzuzo yokusebenza nhlobo kulokhu. Eqinisweni, kuyoba nokulahlekelwa okuncane kokusebenza kusuka phezulu kwe-controller ye-RAID.
RAID 1 + 0 noma 10
Lokhu kuyinkimbinkimbi enzima kakhulu kokubili amazinga we-RAID 0 nezinga 1 . Ngokuphumelelayo, isilawuli sidinga okungenani ubuncane bama-drives amane ukuze isebenze kule modi ngoba lokho okuzokwenziwa yenzani amaphuzu amabili okushayela. Iqoqo lokuqala lokushayela luhlanganisa uhlu oluhambisana nedatha phakathi kwalaba ababili. Isethi yesibili yokushayela ibuye iboniswe kodwa ihlelwe ibe yindawo yokuqala. Lokhu kunikeza kokubili ukulungiswa kwedatha nokusebenza okuzuzayo. Ngezansi isibonelo sokuthi idatha ingabhalwa kanjani kuma-drives amane usebenzisa lolu hlobo lokusetha:
| Drayivu 1 | Drayivu 2 | Drayivu 3 | Drayivu 4 | |
|---|---|---|---|---|
| Vimba 1 | 1 | 1 | 2 | 2 |
| Vimba 2 | 3 | 3 | 4 | 4 |
| Vimba 3 | 5 | 5 | 6 | 6 |
Ukuze uthembeke, lokhu akuyona imodi efiselekayo ye-RAID ezosebenza ohlelweni lwekhompyutha. Ngenkathi ihlinzekela ukuthuthukiswa kokusebenza okwamanje akuyona into enhle ngenxa yesamba esikhulu se-overhead ohlelweni. Ngaphezu kwalokho, kuyindawo enkulu yokuchitha isikhala njengoba i-driy array izoba yingxenye engaphezu kwesigamu samandla azo zonke izinjini ezihlanganisiwe. Uma kusetshenziselwa ukushayela okungahambisani kahle, ukusebenza kuzokhawulelwa kokuhamba kancane kokushayela kanye nomthamo kuzoba kabili idrayivu encane kakhulu.
RAID 5
Leli lizinga eliphakeme kakhulu le-RAID elingatholakala kumasistimu ekhompiyutha yabathengi futhi kuyindlela ephumelela kakhulu yokwandisa amandla kanye nokuvuselela. Ifeza lokhu ngokusebenzisa inqubo yokwaziswa kwedatha ngobunye. Kudingeka ukuhamba okungenani kwezintathu ukwenza lokhu njengoba idatha ihlukaniswe yaba yimivimbo eziningana zokushayela kepha lapho ibanga elilodwa ngaphesheya komgqa libekelwe eceleni. Ukuze uchaze lokhu okungcono, vumela kuqala ubone ukuthi idatha ingabhalwa kanjani phakathi kwamashayela amathathu:
| Drayivu 1 | Drayivu 2 | Drayivu 3 | |
|---|---|---|---|
| Vimba 1 | 1 | 2 | p |
| Vimba 2 | 3 | p | 4 |
| Vimba 3 | p | 5 | 6 |
Empeleni, umlawuli wedrayivu uthatha i-chunk yedatha ezobhalwa kuwo wonke amashayela ohlwini. Idatha yokuqala yedatha ifakwe ku-drive yokuqala futhi okwesibili kufakwe okwesibili. I-drive yesithathu ithola ubumbano obuncane obuqhathaniswa nedatha kanambambili kokuqala nangesibili. Ngezibalo zobunambambili, une-0 nje ne-1. I-process boolean yezibalo inqunywe ukuqhathanisa amabhuzu. Uma lezi zingxenye zingeza kufinyelela kwinombolo (0 + 0 noma 1 + 1) khona-ke i-parity bit izoba zero. Uma lezi zingxenye zingeza kwinombolo engaqondakali (1 + 0 noma 0 + 1) khona-ke i-parity bit izoba eyodwa. Isizathu salokhu ukuthi uma enye yezinkomba ihluleka, umlawuli angakwazi ukuthola lokho idatha engekho. Isibonelo, uma idrayivu eyodwa ihluleka, ishiya nje ukushayela amabili nobathathu, futhi ukushayela kabili kunomlando wedatha owodwa bese ushayela abathathu unobungozi bunye, khona-ke ukuvimba kwedatha elahlekile ku-drive eyodwa kufanele ibe yero.
Lokhu kunikeza ukulungiswa kwemininingwane ephumelelayo evumela ukuthi yonke idatha ibuyiselwe uma kwenzeka ukuhluleka kwedrayivu. Manje kumasethi wezinkampani eziningi, ukuhluleka kuzokwenze kube nesistimu engekho ngoba ayikho esimweni esisebenzayo. Ukuze uthole uhlelo olusebenzayo, kubalulekile ukufaka esikhundleni se-drive ehlulekile nge-drive entsha. Khona-ke inqubo yokwakhiwa kwedatha kumele yenziwe ezingeni lesilawuli esizokwenza umsebenzi oguqukayo we-boolean ukuze ubuyekeze idatha kudrayivu elahlekile. Lokhu kungathatha isikhathi esithile, ikakhulukazi kumashayela omandla amakhulu kodwa okungenani kuyatholakala.
Manje umthamo we-RAID 5 uxhomeke kunani lezinkampani ezihambayo kanye nomthamo wazo. Ngokuphindaphindiwe, lo mkhakha uvinjelwe umthamo omncane kunazo zonke ukuhamba kwe-array ngakho-ke kungcono ukusebenzisa amashayela afanelanayo. Isikhala sokugcina esisebenzayo silingana nenombolo yezimoto ngaphandle kwesinye isikhathi umthamo ophansi kakhulu. Ngakho-ke ngokwemigomo, yi (n-1) * I-Capacitymin . Ngakho-ke, uma unamakholi amathathu we-2GB ku-RAID 5 uhlaka, umthamo wesilinganiso uzoba yi-4GB. Olunye uhlobo lwe-RAID olu-5 olusebenzisa amashayeli amane we-2GB luyoba ne-6GB yamandla.
Manje ukusebenza kwe-RAID 5 kunzima kakhulu kunamanye amafomu we-RAID ngenxa yenqubo ye-boolean okumelwe yenziwe ukuze kudalwe i-parity bit lapho idatha ibhalwa kumashayela. Lokhu kusho ukuthi ukusebenza okubhaliwe kuyoba ngaphansi kwe-RAID 0 ehleliwe nenombolo efanayo yokushayela. Funda ukusebenza, ngakolunye uhlangothi, aluhlupheki kakhulu njengoba kubhaliwe ngoba inqubo ye-boolean ayenziwanga ngoba ifunda idatha eqondile evela kumashayeli.
Inkinga Enkulu Nayo Zonke Izilungiselelo Zama-RAID
Sixoxisane ngezinzuzo ezihlukahlukene nezindleko zezinga ngalinye le-RAID elingasetshenziswa kumakhompyutha akho kodwa kukhona enye inkinga abantu abaningi abangayiqapheli uma kuziwa ekudaleni amasu we-drive we-RAID. Ngaphambi kokusetha kwe-RAID kungasetshenziswa, okokuqala kumele kwakhiwe isofthiwe ye-hardware isilawuli noma ngaphakathi kwesofthiwe yesistimu yokusebenza. Lokhu kuqala ukufaka ukufometha okukhethekile okudingekayo ukulandelela kahle ukuthi idatha izobhalwa kanjani futhi ifunde ku-drive.
Lokhu kungabonakali njengenkinga kodwa uma ngabe udinga ukuguqula indlela ofuna isakhiwo sakho se-RAID esilungisiwe. Isibonelo, sithi uhamba phansi kwedatha futhi ufuna ukwengeza idrayivu eyengeziwe ye-RAID 0 noma i-RAID 5. Ezimweni eziningi, ngeke ukwazi ukuqala kabusha kabusha i-RAID array ezosusa noma iyiphi idatha egcinwe kulawo mayela. Lokhu kusho ukuthi kufanele uvuselele ngokugcwele imininingwane yakho, engeza idrayivu entsha, ubuyekeze kabusha i-driy array, ifomethi ehamba phambili, bese ubuyisela idatha yakho yangempela emuva kwidrayivu. Lokho kungaba inqubo ebuhlungu kakhulu. Ngenxa yalokho, qiniseka ukuthi unamaphakheji ahleliwe ngendlela oyifunayo okokuqala.