Kwanan nan an fitar da labarai cewa mahaliccin kwayar Linux, "Linus Torvalds" an karɓa a cikin babban reshe (a kan wane nau'i ne aka kafa 5.4) aiwatar da dm-clone module tare da aiwatar da sabon mai sarrafawa dangane da Na'urar-Mapper.
Wannan sabuwar shawarar don kwayar Linux zai ba ka damar clone wani data kasance toshe na'urar. Moduleungiyar ta ba da izinin ƙirƙirar kwafin gida bisa tushe a kan na'urar toshe-kawai wanda za'a iya rubuta shi yayin aikin cloning.
A matsayin aikace-aikacen al'ada na tsarin da aka tsara don Linux Kernel "Dm-clone" yana nufin rufe cibiyar sadarwa na na'urorin fayil masu nisa a yanayin karanta-kawai da aikin I / O tare da jinkiri mai tsawo, zuwa na'urar cikin gida mai sauri wanda ke tallafawa rikodi da buƙatun sarrafawa tare da jinkiri kaɗan.
Tare da shi yana ba da damar ɗaga na'urar cloned kuma fara amfani da shi nan da nan bayan ƙirƙirar ta, ba tare da jiran tsarin canja wurin bayanai ya ƙare ba.
Yayin da a gefe guda za a ci gaba da yin kwafin bayanai a bango, a layi daya tare da shigarwar / fitarwa da aka ƙirƙira yayin isa ga sabon na'urar.
Babban abin da ake amfani da shi don dm-clone shine a sanya latency mai yuwuwa, na'urar kulle nau'in fayil irin wacce za'a iya amfani da ita akan na'urar na farko wacce za'a iya rubutawa.
Alal misali dm-clone za a iya amfani da shi don dawo da haɗewar ajiyar ajiya zuwa ga hanyar sadarwar da ake samu ta hanyar ladabi kamar NBD, Fiber Channel, iSCSI da AoE akan ajiyar cikin gida dangane da SSD ko NVMe.
An inganta lambar dm-clone don ƙaramin rubutun bazuwar wanda girmansa yayi daidai da girman toshe (4K ta tsohuwa).
Yayin aiwatar da cloning, karanta buƙatun zai haifar da buƙatar kai tsaye don bayanai daga na'urar da aka sanyawa kuma rubuta buƙatun da suka shafi yankunan da ba a daidaita su ba za a jinkirta har sai an kammala shigar da bulolin buƙatun da ba a buƙata ba ( ayyukan lodawa don abubuwan da suka shafi rikodin suna farawa nan take).
Tubalan da aka cire ta aikin "jefar" an cire su daga aikin kwafin (bayan hawa, mai amfani zai iya aiwatar da "fstrim / mnt / cloned-fs" don guje wa kwafin tubalan da ba a amfani da su a cikin FS).
Bayani game da canje-canje da bayanai a cikin ɗakunan da aka ɗora ana adana su a cikin teburin metadata na gida daban.
Bayan cloning an kammala, mai amfani yana karɓar cikakken kwafin aiki na tushen na'urar, yana nuna duk canje-canjen da aka yi tun farkon fara cloning.
Za'a iya sauke tebur tare da metadata na clone bayan aiki tare ta hanyar maye gurbinsa da teburin layuka waɗanda kai tsaye suke nuna bayanan zuwa sabuwar na'urar.
Babban banbanci daga Unionfs da OverlayFS tushen mafita shine cewa dm-clone yana aiki a matakin na'urar toshe, ba tare da la'akari da tsarin fayil ɗin da aka yi amfani da shi akan wannan na'urar ba, kuma yana samar da cikakken kwafin na'urar da ke tushen kuma baya sanya ƙarin layin. inda ake bin canje-canje.
Ba kamar dm-madubi ba, an tsara dm-clone module don aiki kawai tare da ɓangaren asali a yanayin karanta kawai, ba tare da fassara ayyukan rubutu zuwa gare shi ba.
A cikin dm-hoto, ba a ƙirƙirar cikakken kwafi kuma ba a tallafawa kwafin bango. A cikin dm-cache, ba a ƙirƙiri cikakken kwafi ba, ana tura ayyukan rubutawa, kuma an rage aiki zuwa abubuwan adanawa. Aiki mafi kusa shine dm-siriri.
dm-clone yana amfani da dm-kcopyd don kwafe ɓangarorin na'urar tushe zuwa na'urar da ake so. Ta hanyar tsoho, ana bayar da buƙatun kwafin girman daidai da girman yankin.
Ana iya amfani da sako na 'hydration_batch_size <#regions>' don daidaita girman wadannan buƙatun kwafin. Sizeara girman adadin hydration yana haifar da dm-clone yana ƙoƙarin haɗa yankuna masu haɗuwa wuri ɗaya, don haka muke tattara kwafin bayanai daga waɗannan yankuna da yawa.
Source: https://git.kernel.org