Mene ne RAID?

RAID wani bayani ne wanda aka samo asali na asusun tallace-tallace na cibiyar sadarwar don hanyar samar da babban ajiya a farashin ƙananan. Da mahimmanci, zai ɗauki ƙananan kayan aiki mai wuya kuma ya haɗa su ta hanyar mai sarrafawa don samar da wata babbar hanyar aiki. Wannan shi ne abin da RAID ya ke nufi: jimlar jigilar kayan aiki maras tsada ko disks. Don cimma wannan, ana buƙatar software na musamman da masu kula domin gudanar da bayanan da aka rarraba tsakanin daban-daban.

Ƙarshe, ikon sarrafawa na tsarin kwamfutarka nagari ya yarda da siffofin da za su tace hanyar shiga cikin kasuwar kwamfutarka ta sirri .

Yanzu RAID ajiya zai iya zama software ko hardware na tushen , kuma za a iya amfani dashi ga dalilai daban-daban. Wadannan sun haɗa da damar, tsaro, da kuma aikin. Ƙarfin abu mai sauƙi ne wanda yake yawanci ya shafi kowane nau'in RAID saitin amfani. Alal misali, ana iya haɗin aiki biyu na aiki tare a matsayin hanya ɗaya zuwa tsarin sarrafawa yadda ya kamata a yi amfani da kwamfutarka mai sauƙi wanda sau biyu ne. Ayyukan aikin wani mahimman dalilin da ake amfani da saitin RAID akan kwamfuta na sirri. A cikin misalin nau'i biyu da ake amfani dashi a matsayin ƙila guda ɗaya, mai sarrafa zai iya raba kundin bayanan bayanai zuwa sassa biyu sa'annan ya sanya ɗayan waɗannan sassan a rarraba. Wannan ya sauƙaƙe aikin yin rubutu ko karanta bayanan akan tsarin ajiya. A ƙarshe, RAID za a iya amfani dashi don tsaro na bayanai.

Anyi wannan ta amfani da wasu daga cikin sararin samaniya a kan masu tafiyarwa don rufe ainihin bayanan da aka rubuta zuwa duka biyu. Har yanzu, tare da tafiyarwa biyu za mu iya sanya shi don an rubuta bayanai zuwa duka biyu. Saboda haka, idan kullun ya kasa kasa, ɗayan yana da bayanai.

Dangane da manufofin ajiyar ajiya wanda kake son hadawa don tsarin kwamfutarka, zaka yi amfani da ɗaya daga cikin matakan RAID don cimma burin nan uku.

Ga wadanda suke yin amfani da tukuru mai kwakwalwa a cikin kwamfutar su , aikin zai yiwu ya zama karin batun fiye da damar. A wani gefe kuma, waɗanda suke yin amfani da ƙwaƙwalwar kwaskwarima suna son hanyar da za su dauki ƙananan tafiyarwa kuma su haɗa su tare don ƙirƙirar ƙira guda ɗaya. Don haka, bari mu dubi nauyin RAID da za a iya amfani dashi tare da kwamfuta na sirri.

RAID 0

Wannan shi ne mafi ƙasƙanci na RAID kuma hakika ba ya bayar da wani nau'i na redundancy wanda shine dalilin da ya sa aka kira shi matakin 0. Ainihin, RAID 0 tana ɗaukar kora biyu ko fiye kuma ya sanya su tare don samar da babbar hanyar motsi. Ana samun wannan ta hanyar mai sarrafawa da ake kira tsiri. Rukunan bayanan bayanai sun rushe zuwa cikin bayanan bayanai sannan an rubuta su a duk fadin tafiyarwa. Wannan kyauta yana karuwa saboda ana iya rubuta bayanai a lokaci ɗaya zuwa ga tafiyarwa ta hanyar mai sarrafawa yadda ya kamata ya ninka gudun daga masu tafiyarwa. Da ke ƙasa akwai misali na yadda wannan zai yi aiki a cikin bangarori uku:

Drive 1 Drive 2 Drive 3
Block 1 1 2 3
Block 2 4 5 6
Block 3 7 8 9


Domin RAID 0 yayi aiki yadda ya kamata domin bunkasa wasan kwaikwayon na tsarin, kana buƙatar gwadawa kuma yayi daidai da tafiyarwa. Kowace gwagwarmaya yana da nauyin nauyin ajiya da kuma wasan kwaikwayo.

Idan ba suyi ba, to hakan za a iyakance su zuwa mahara daga cikin mafi ƙanƙanci na tafiyarwa da kuma yin aiki ga mafi jinkirin masu tafiyarwa saboda dole ne a jira dukkan ratsan da za'a rubuta kafin motsi zuwa saiti na gaba. Zai yiwu a yi amfani da kullun da ba a yi ba amma a wannan yanayin, saitin JBOD zai iya zama mafi tasiri.

JBOD yana tsaye ne kawai don ƙunshi kayan aiki da kuma yadda ya kamata shi ne kawai tarin tafiyarwa da za a iya samun dama daga juna amma ya bayyana a matsayin ɗayan kaya ɗaya zuwa tsarin aiki. Wannan yana samuwa ta musamman ta hanyar samun bayanan bayanai tsakanin masu tafiyarwa. Sau da yawa ana kiran wannan SPAN ko BIG.

Da kyau, aikin yana ganin su duka ɗaya ne kawai sai dai an rubuta tubalan a fadin faifai na farko har sai ya cika, sa'an nan kuma ci gaba zuwa na biyu, sannan na uku, da dai sauransu. Wannan yana da amfani don ƙara ƙarin iya aiki a cikin tsarin kwamfutar da ke ciki. tare da na'urori masu yawa dabam dabam amma bazai kara yawan aikin wasan kwaikwayo ba.

Babban matsala tare da RAID 0 da JBOD setups shine tsaro bayanai. Tun da kana da kullun da yawa, sauƙi na cin hanci da rashawa ya karu saboda kana da karin maki na rashin nasara . Idan kowane kullun a RAID 0 tsarewar ya kasa, duk bayanan ya zama m. A cikin JBOD, ƙwaƙwalwar drive zai haifar da asarar duk wani bayanan da ya faru akan wannan drive. A sakamakon haka, ya fi dacewa ga waɗanda suke so su yi amfani da wannan hanyar ajiya don samun wasu hanyoyi don ajiye bayanai.

RAID 1

Wannan shine matakin farko na RAID kamar yadda yake samar da cikakken tsari na bayanan da aka adana a kan tsararren. Anyi wannan ta hanyar tsari wanda ake kira mirroring. Da kyau, duk bayanan da aka rubuta zuwa tsarin din an kwashe zuwa kowane rukuni a matakin jigon 1. Wannan nau'i na RAID an yi shi ne kawai tare da kawai ƙungiyoyi kamar ƙara ƙarin ƙwaƙwalwar bazai ƙara wani ƙarin ƙarfin aiki ba, kawai ƙaddamarwa. Domin mafi kyau ya ba da misalin wannan, a nan akwai ginshiƙi wanda ya nuna yadda za a rubuta shi zuwa biyu:

Drive 1 Drive 2
Block 1 1 1
Block 2 2 2
Block 3 3 3


Domin samun amfani mafi inganci daga tsarin saiti na RAID 1, tsarin zai sake amfani da kayan aiki wanda ya dace wanda ya raba wannan damar da kuma yadda ya dace.

Idan ana amfani da kayan aiki ba tare da izini ba, to, ƙarfin tashar wutar lantarki zai zama daidai da ƙananan ƙarfin motsi a cikin tsararren. Alal misali, idan ana amfani da rabi daya da rabi da kuma wata hanya ta hanya a cikin rukunin RAID 1, ikon wannan tsararren a kan tsarin ba zai zama guda ɗaya kawai ba.

Wannan matakin RAID yana da matukar tasiri ga tsaro na bayanai saboda kayan aiki guda biyu daidai yake. Idan ɗaya daga cikin kwando biyu ya kasa, to, ɗayan yana da cikakken bayanai na ɗayan. Matsalar da irin wannan saitin yana ƙayyade wane ɓangaren nawa ya kasa saboda sau da yawa ajiya ya zama m lokacin da ɗayan biyu ya kasa kasa kuma ba za a iya dawowa da kyau ba har sai an saka sabon drive a wurin wanda ya kasa da kuma dawowa tsari yana gudana. Kamar yadda aka ambata a baya, kuma babu wani karfin yin amfani da wannan daga wannan. A gaskiya ma, za a yi hasara ta haɓaka daga mai girma na mai kula da RAID.

RAID 1 + 0 ko 10

Wannan wani abu mai rikitarwa ne na duka RAID matakai 0 da matakin 1 . Da mahimmanci, mai kula da buƙatar yana buƙatar aƙuda mafi mahimmanci huɗu don aiki a cikin wannan yanayin saboda abin da zai yi shi ne yin nau'i biyu na tafiyarwa. Saitin farko na tafiyarwa yana nuna nauyin haɗin ɗigon bayanan da ke tsakanin su biyu. Sanya na biyu na tafiyarwa an kuma kwatanta shi amma an saita su zama tsiri na farko. Wannan yana bada duka bayanan bayanai da kuma samun nasara. Da ke ƙasa akwai misali na yadda za a rubuta bayanai a cikin kwasfa huɗu ta hanyar amfani da wannan saitin:

Drive 1 Drive 2 Drive 3 Drive 4
Block 1 1 1 2 2
Block 2 3 3 4 4
Block 3 5 5 6 6


Don gaskiya, wannan ba hanya ce mai kyau na RAID don gudana a kan tsarin kwamfuta ba. Yayinda yake samar da wasu ayyuka yana ƙarfafa shi ba shi da kyau saboda yawan adadin da ke cikin tsarin. Bugu da ƙari, yana da mummunan sararin samaniya a matsayin fitinar kayan aiki kawai a mafi yawan rabin damar da dukkanin tafiyarwa suka haɗa. Idan ana amfani da kayan aiki ba tare da izini ba, aikin zai iyakance ga jinkirin tafiyarwa kuma iyawa zai iya zama sauƙi mafi ƙanƙanci.

RAID 5

Wannan shi ne matakin mafi girma na RAID wanda za'a iya samuwa a cikin tsarin kwamfuta na masu amfani da kuma hanya mafi mahimmanci don haɓaka ƙarfin aiki da sakewa. Ya samu wannan ta hanyar aiwatar da labarun bayanai tare da parity. Yawancin kayan aiki guda uku ya zama dole don yin haka yayin da aka raba bayanai akan ratsi a kan dama daga cikin tafiyarwa amma sai an raba guda ɗaya a cikin sashin layi don parity. Don bayanin wannan mafi kyau, bari mu fara kallon yadda za a iya rubuta bayanai a fadin tafiyar uku:

Drive 1 Drive 2 Drive 3
Block 1 1 2 p
Block 2 3 p 4
Block 3 p 5 6


Ainihin, mai sarrafa motsi yana daukar nauyin bayanan da za a rubuta a cikin dukan tafiyarwa a cikin tsararren. An sanya jigon bayanai na farko a kan kaya na farko kuma an sanya na biyu a kan na biyu. Kashi na uku yana samun daidaituwa wanda shine ainihin kwatanta bayanai na binary a kan na farko da na biyu. A cikin lissafin lissafi, kana da 0 da kuma 1. An yi matakan lissafin lissafi don kwatanta raguwar. Idan biyu sun ƙara har zuwa lamba (0 + 0 ko 1 + 1) to, bitar bit ba zata zama ba. Idan waɗannan biyu sun ƙara zuwa lambar da ba kome ba (1 + 0 ko 0 + 1) to, ɗanity bit zai zama ɗaya. Dalilin haka shi ne cewa idan ɗaya daga cikin tafiyarwa bai kasa kasa ba, mai kula zai iya gane abin da aka ɓace. Alal misali, idan kullun ya ɓace, barin kawai a kwashe biyu da uku, sa'annan kuma a kwashe biyu yana da asusun bayanai na daya sannan kuma ƙira uku yana da ɓangaren sashin layi daya, to, ɓangaren da aka ɓace a kan drive dole ne ba kome.

Wannan yana samar da cikakken bayanan bayanan da ya ba da izinin damar dawo da dukkan bayanai a yayin da aka samu nasarar cin nasara. Yanzu saboda mafi yawan masu amfani da saitunan, rashin cin nasara zai haifar da tsarin bai kasance ba saboda ba a cikin tsarin aiki ba. Domin samun aikin tsarin, dole ne a maye gurbin kullun da ya ɓace tare da sabuwar drive. Sa'an nan kuma dole ne a aiwatar da tsari na sake fasalin bayanai a matakin mai kulawa wanda zai yi aiki na baya don sake tattara bayanai a kan ɓataccen jirgin. Wannan na iya ɗaukar lokaci, musamman don ƙwaƙwalwar haɓaka mai girma amma yana da akalla dawowa.

Yanzu karfin rAID 5 yana dogara ne akan adadin tafiyarwa a cikin tsararru da damar su. Bugu da ƙari, ƙaddamarwar ta ƙayyade ta ƙananan ƙarfin motsi a cikin tsararren don haka ya fi dacewa don amfani da kayan aiki daidai. Tsarin sararin samaniya yana daidai da yawan masu tafiyarwa sau ɗaya sau sauƙi mafi ƙarfin iya aiki. Saboda haka a cikin math, yana da (n-1) * Capacitymin . Saboda haka, idan kana da matuka 2GB a RAID 5, jimlar zata iya zama 4GB. Wani rukunin RAID 5 wanda yayi amfani da na'urorin 2GB na 2GB zai sami 6GB na iya aiki.

Yanzu aikin RAID 5 yafi rikitarwa fiye da wasu nau'o'in RAID saboda tsari na boolean wanda dole ne a yi domin ƙirƙirar layin bit lokacin da aka rubuta bayanai zuwa ga masu tafiyarwa. Wannan yana nufin cewa yin rubutun zai zama kasa da rukunin RAID 0 tare da wannan adadi na tafiyarwa. Karanta aikin, a gefe guda, ba ya wahala kamar yadda rubuce-rubucen yake ba saboda ba a yi amfani da tsari ba saboda yana karanta cikakkun bayanai daga masu tafiyarwa.

Babban Batutuwa Tare da Duk RAID Saitin

Mun tattauna batutuwan da suka hada da RAID da za a iya amfani dashi a kwakwalwa na sirri amma akwai wata matsala da mutane da dama basu fahimta ba game da samar da saitin RAID drive. Kafin a iya amfani da saitin RAID, dole ne a gina ta farko ta hanyar software mai sarrafa kayan aiki ko cikin software na tsarin aiki. Wannan ya ƙaddamar da tsari na musamman wanda zai buƙata yadda za a rubuta bayanan da kuma karanta a kan drive.

Wannan mai yiwuwa ba sauti kamar matsala amma yana da idan har ma kuna buƙatar canza yadda kuke son RAID mahalarta haɓaka. Alal misali, a ce kuna gudu akan bayanai kuma kuna so ku ƙara wani kaya don RAID 0 ko RAID 5. A mafi yawancin lokuta, ba za ku iya ba tare da fara sake farawa da rukunin RAID wanda zai cire duk wani bayanan da aka adana a cikin waɗannan na'urorin. Wannan yana nufin cewa dole ka cika bayananka, ƙara sabon kundin, sake tsara tsarin tsararrakin, tsarin da zai fitar da tsararraki, sa'an nan kuma mayar da bayanan asalinka zuwa drive. Wannan zai iya zama wata matsala mai zafi. A sakamakon haka, tabbatar da cewa kana da tsararren tsararraki kamar yadda kake so a karo na farko da kakeyi.