Gabatarwa zuwa SSD. Part 2. Interface

В kashi na karshe sake zagayowar "Gabatarwa ga SSD" mun yi magana game da tarihin bayyanar diski. Sashe na biyu zai yi magana game da mu'amala don mu'amala da tuƙi.

Sadarwa tsakanin na'ura mai sarrafawa da na'urorin haɗi yana faruwa ne bisa ga ƙayyadaddun ƙayyadaddun ƙa'idodin da ake kira interfaces. Waɗannan yarjejeniyoyin suna tsara matakin hulɗar jiki da software.

Interface - saitin hanyoyin, hanyoyin da ka'idojin hulɗa tsakanin abubuwan tsarin.

Aiwatar da aikin mu'amala ta zahiri yana shafar sigogi masu zuwa:

• hanyar sadarwa ta hanyar sadarwa;
• matsakaicin adadin na'urorin da aka haɗa lokaci guda;
• yawan kurakuran da ke faruwa.

An gina hanyoyin haɗin diski a kan I/O tashoshin jiragen ruwa, wanda shine kishiyar ƙwaƙwalwar I/O kuma baya ɗaukar sarari a sararin adireshi na processor.

Daidaitawa da tashar jiragen ruwa na serial

Dangane da hanyar musayar bayanai, tashoshin I / O sun kasu kashi biyu:

• layi daya;
• m.

Kamar yadda sunan ke nunawa, layin layi ɗaya yana aika kalmar inji a lokaci ɗaya, wanda ya ƙunshi raƙuman ruwa da yawa. Tashar jiragen ruwa mai kama da juna ita ce hanya mafi sauƙi don musayar bayanai, saboda baya buƙatar hadaddun hanyoyin kewayawa. A cikin mafi sauƙi, kowane ɗan kalmar na'ura ana aika shi akan layin siginar kansa, kuma ana amfani da layin siginar sabis guda biyu don amsawa: An shirya bayanai и An karɓi bayanai.

Matsakaicin mashigai, a kallon farko, sikelin da kyau: ƙarin layukan sigina - ƙarin ragowa ana watsa su a lokaci guda kuma, sabili da haka, mafi girma kayan aiki. Sai dai kuma saboda karuwar layukan sigina, tsangwama na faruwa a tsakaninsu, wanda ke haifar da gurbatar sakonnin da ake yadawa.

Serial tashoshin jiragen ruwa ne akasin a layi daya. Ana aika bayanai guda ɗaya a lokaci guda, wanda ke rage adadin layukan sigina, amma yana dagula mai sarrafa I/O. Mai sarrafa na'ura yana karɓar kalmar inji a lokaci ɗaya kuma dole ne ya watsa bit ɗaya a lokaci guda, kuma mai sarrafa na'urar dole ne ya karɓi raƙuman ruwa ya adana su a cikin tsari iri ɗaya.

Ƙananan layukan sigina suna ba ku damar ƙara yawan watsa saƙon ba tare da tsangwama ba.

SCSI

Karamin Tsarin Tsarin Kwamfuta (SCSI) ya bayyana a baya a cikin 1978 kuma an tsara shi da farko don haɗa na'urori na bayanan martaba daban-daban zuwa tsari guda. Ƙididdigar SCSI-1 ta tanadar don haɗin har zuwa na'urori 8 (tare da mai sarrafawa), kamar:

• na'urorin daukar hoto;
• tef drives (streamers);
• kayan aikin gani;
• faifan diski da sauran na'urori.

SCSI da farko ana kiranta Shugart Associates System Interface (SASI), amma kwamitin ma'auni ba zai amince da sunan bayan kamfanin ba, kuma bayan ranar da aka fara tunanin, an haifi sunan Small Computer Systems Interface (SCSI). Mahaifin SCSI, Larry Boucher, ya yi nufin a fayyace gagaratun " sexy", amma Dal Allan karanta "sсuzzy" ("gaya"). Daga baya, lafazin "gaya" ya kasance da ƙarfi a cikin wannan ma'auni.

A cikin kalmomin SCSI, na'urorin da aka haɗa sun kasu zuwa nau'i biyu:

• masu farawa;
• manufa na'urorin.

Mai farawa yana aika umarni zuwa na'urar da aka yi niyya, wanda sannan ya aika da martani ga mai farawa. An haɗa masu farawa da makasudi zuwa bas na SCSI na kowa, wanda ke da bandwidth na 1 MB/s a cikin ma'aunin SCSI-5.

“Bas ɗin gama gari” da aka yi amfani da shi yana ɗaukar hani da yawa:

• a ƙarshen bas, ana buƙatar na'urori na musamman - masu ƙarewa;
• bandwidth na bas yana raba tsakanin duk na'urori;
• Matsakaicin adadin na'urorin da aka haɗa lokaci guda yana iyakance.

Ana gano na'urori akan bas ɗin ta wata lamba ta musamman da ake kira SCSI Target ID. Kowace naúrar SCSI a cikin tsarin ana wakilta ta da aƙalla na'ura mai ma'ana ɗaya, wacce ke magana da lamba ta musamman a cikin na'urar ta zahiri. Lamba Naúrar Hankali (LUN).

Ana aika umarni a cikin SCSI a cikin tsari umarnin bayanin tubalan (Tsarin Bayanin Umurni, CDB), wanda ya ƙunshi lambar aiki da sigogin umarni. Ma'auni ya bayyana fiye da umarni 200, zuwa kashi huɗu:

• M - dole ne a goyan bayan na'urar;
• ZABI - za a iya aiwatarwa;
• takamaiman mai siyarwa - amfani da wani takamaiman masana'anta;
• Rashin hankali - umarni mara amfani.

Daga cikin umarni da yawa, uku kawai daga cikinsu sun zama tilas ga na'urori:

• AN SHIRYA RASHIN GWADA - duba shirye-shiryen na'urar;
• NEMAN HANKALI - yana buƙatar lambar kuskure na umarnin da ya gabata;
• BINCIKE - nemi manyan halayen na'urar.

Bayan karɓa da sarrafa umarnin, na'urar da aka yi niyya ta aika lambar matsayi ga mai ƙaddamarwa, wanda ke bayyana sakamakon aiwatarwa.

Ƙarin haɓakawa na SCSI (SCSI-2 da Ultra SCSI ƙayyadaddun bayanai) ya faɗaɗa jerin umarnin da aka yi amfani da su kuma ya ƙara adadin na'urorin da aka haɗa har zuwa 16, da kuma musayar bayanai akan bas din har zuwa 640 MB/s. Tun da SCSI wani layi ne na layi ɗaya, haɓaka mitar musayar bayanai yana da alaƙa da raguwa a matsakaicin tsayin kebul kuma ya haifar da rashin jin daɗi a cikin amfani.

An fara da ma'auni na Ultra-3 SCSI, goyon baya don "fulogi mai zafi" ya bayyana - na'urorin haɗi lokacin da wuta ke kunne.

Sanannen SCSI SSD na farko shine M-Systems FFD-350, wanda aka saki a cikin 1995. Faifan yana da tsada kuma ba a yi amfani da shi sosai ba.

A halin yanzu, layi daya SCSI ba sanannen sigar faifai ba ne, amma saitin umarni har yanzu ana amfani da shi sosai a cikin mu'amalar USB da SAS.

ATA/PATA

dubawa ATA (Advanced Technology Attachment), kuma aka sani da HOOF (Parallel ATA) Western Digital ne ya haɓaka a cikin 1986. Sunan tallace-tallace don ma'auni na IDE (Eng. Integrated Drive Electronics - "electronics gina a cikin drive") ya jaddada wani muhimmin mahimmanci: an haɗa mai sarrafa kayan aiki a cikin motar, kuma ba a kan wani katako na fadada ba.

Shawarar sanya mai sarrafawa a cikin tuƙi ya warware matsaloli da yawa lokaci guda. Na farko, nisa daga tuƙi zuwa mai sarrafawa ya ragu, wanda ya shafi aikin tafiyarwa sosai. Abu na biyu, ginannen mai sarrafawa an "kaifi" kawai don wani nau'in tuƙi kuma, bisa ga haka, ya kasance mai rahusa.

ATA, kamar SCSI, tana amfani da hanyar I/O daidai gwargwado, wanda ke nunawa a cikin igiyoyin da aka yi amfani da su. Haɗin faifai ta amfani da ƙirar IDE yana buƙatar igiyoyi 40-core, kuma ana kiranta da igiyoyi masu lebur. Ƙarin ƙayyadaddun bayanai na baya-bayan nan suna amfani da stubs 80-waya, fiye da rabi waɗanda suke madaukai na ƙasa don rage tsangwama a manyan mitoci.

Akwai mahaɗa biyu zuwa huɗu akan kebul ɗin ATA, ɗaya daga cikinsu yana jone da motherboard, saura kuma akan faifai. Lokacin haɗa na'urori biyu a cikin madauki ɗaya, dole ne a saita ɗayan su azaman Master, na biyu kuma kamar Bawa. Na'urar ta uku za a iya haɗa ta cikin yanayin karanta kawai.

Matsayin mai tsalle yana ƙayyade rawar wani na'ura. Kalmomin Jagora da Bawa dangane da na'urori ba daidai ba ne, tunda dangane da mai sarrafawa, duk na'urorin da aka haɗa bayi ne.

Wani sabon abu na musamman a cikin ATA-3 shine bayyanar Kulawa da Kai, Fasahar Bincike da Rahoto (SMART). Kamfanoni biyar (IBM, Seagate, Quantum, Conner, da Western Digital) sun haɗu da ƙarfi da daidaitattun fasahar tantance lafiyar lafiya.

Taimako don ingantattun abubuwan tafiyar da jihar ya kasance tun daga sigar 1998 na ma'auni, wanda aka saki a cikin 33.3. Wannan sigar daidaitattun tana ba da ƙimar canja wurin bayanai har zuwa XNUMX MB/s.

Ma'auni yana gabatar da ƙaƙƙarfan buƙatu don igiyoyin ATA:

• plum dole ne ya zama lebur;
• Matsakaicin tsayin jirgin ƙasa inci 18 (santimita 45.7).

Jirgin kasa gajere da fadi bai dace ba kuma yana tsoma baki tare da sanyaya. Ya zama da wahala don ƙara mitar watsawa tare da kowane nau'i na ma'auni na gaba, kuma ATA-7 ya warware matsalar da gaske: an maye gurbin layi na layi tare da serial daya. Bayan haka, ATA ta sami kalmar Parallel kuma ta zama mai suna PATA, kuma sigar ta bakwai ta ma'aunin ta sami wani suna daban - Serial ATA. Lambar sigar SATA ta fara daga ɗaya.

SATA

An gabatar da ma'aunin Serial ATA (SATA) a ranar 7 ga Janairu, 2003 kuma ya magance matsalolin magabata tare da canje-canje masu zuwa:

• tashar tashar layi daya maye gurbinsu da serial;
• m 80-waya na USB maye gurbinsu da 7-waya;
• "Bas gama gari" an maye gurbinsa tare da haɗin "point-to-point".

Ko da yake SATA 1.0 (SATA/150, 150 MB/s) ya ɗan yi sauri fiye da ATA-6 (UltraDMA/130, 130 MB/s), yunƙurin zuwa sadarwar serial shine "tsara ƙasa" don saurin gudu.

An maye gurbin layukan sigina goma sha shida don watsa bayanai a cikin ATA tare da murɗaɗɗen nau'i biyu: ɗaya don watsawa, na biyu don liyafar. An tsara masu haɗin SATA don su kasance masu juriya ga haɗuwa da yawa, kuma ƙayyadaddun SATA 1.0 ya sanya yuwuwar toshe zafi.

Wasu fil a kan faifai sun fi sauran sauran gajeru. Ana yin wannan don tallafawa "zafin musanya" (Hot Swap). Yayin aiwatar da sauyawa, na'urar ta "rasa" kuma "nemo" layin a cikin tsari da aka riga aka ƙayyade.

Bayan fiye da shekara guda, a cikin Afrilu 2004, an saki sigar na biyu na ƙayyadaddun SATA. Baya ga haɓaka har zuwa 3 Gb/s, SATA 2.0 ta ƙaddamar da fasaha Kwamandan 'Yan Asalin Queuing (NCQ). Na'urori masu goyan bayan NCQ suna iya tsara tsarin aiwatar da umarni masu shigowa da kansu don cimma iyakar aiki.

A cikin shekaru uku masu zuwa, Ƙungiyar Ayyuka ta SATA ta yi aiki don inganta ƙayyadaddun da ake da su, kuma sigar 2.6 ta gabatar da ƙananan haɗin Slimline da micro SATA (uSATA). Waɗannan masu haɗin suna ƙaramin sigar asalin haɗin SATA ne kuma an tsara su don faifan gani da ƙananan faifai a cikin kwamfyutocin.

Yayin da SATA na ƙarni na biyu yana da isasshen bandwidth don HDDs, SSDs sun buƙaci ƙari. A cikin Mayu 2009, an fitar da sigar ta uku ta ƙayyadaddun SATA tare da haɓaka bandwidth zuwa 6 Gb/s.

An biya kulawa ta musamman ga ƙaƙƙarfan tuƙi a cikin bugu na SATA 3.1. Mai haɗin Mini-SATA (mSATA) ya bayyana, wanda aka ƙera don haɗa ƙaƙƙarfan tafiyarwa a cikin kwamfyutoci. Ba kamar Slimline da uSATA ba, sabon haɗin yana kama da PCIe Mini, kodayake bai dace da PCIe ta hanyar lantarki ba. Baya ga sabon mai haɗawa, SATA 3.1 ya yi alfahari da ikon yin layi na umarnin TRIM tare da karantawa da rubuta umarni.

Umurnin TRIM yana sanar da SSD na katangar bayanan da ba sa ɗaukar kaya. Kafin SATA 3.1, wannan umarni zai cire caches kuma ya dakatar da ayyukan I/O, sannan kuma umarnin TRIM ya biyo baya. Wannan hanyar ta lalata aikin faifai yayin aikin sharewa.

Ƙididdigar SATA ba ta ci gaba da ci gaba da saurin girma a cikin saurin samun damar SSDs ba, wanda ke haifar da sulhu a cikin 2013 da ake kira SATA Express a cikin ma'auni na SATA 3.2. Maimakon sake ninka bandwidth na SATA, masu haɓakawa sun yi amfani da bas ɗin PCIe da ake amfani da su sosai, wanda saurinsa ya wuce 6 Gb / s. Direbobi tare da tallafin SATA Express sun sami nasu nau'i nau'i mai suna M.2.

SAS

Ma'auni na SCSI, "gasa" tare da ATA, shima bai tsaya cak ba kuma shekara guda bayan bayyanar Serial ATA, a cikin 2004, an sake haifuwar ta cikin keɓancewar siriyal. Sunan sabon dubawa shine Serial Attached SCSI (SEDGE).

Kodayake SAS ta gaji saitin umarnin SCSI, canje-canjen sun kasance masu mahimmanci:

• serial dubawa;
• 29-waya na USB tare da wutar lantarki;
• aya-to-point dangane

Hakanan an gaji kalmomin SCSI. Har yanzu ana kiran mai sarrafawa mai farawa, kuma ana kiran na'urorin da aka haɗa da manufa. Duk na'urorin da aka yi niyya da mai farawa suna samar da yankin SAS. A cikin SAS, bandwidth haɗin haɗin ba ya dogara da adadin na'urori a cikin yankin, tun da kowace na'ura tana amfani da tashar sadaukar da kanta.

Matsakaicin adadin na'urorin da aka haɗa lokaci guda a cikin yankin SAS, bisa ga ƙayyadaddun bayanai, ya wuce dubu 16, kuma maimakon ID na SCSI, ana amfani da mai ganowa don magancewa. Sunan Duniya (WWN).

WWN wani keɓaɓɓen mai ganowa ne mai tsayin bytes 16, kama da adireshin MAC na na'urorin SAS.

Duk da kamanceceniya tsakanin masu haɗin SAS da SATA, waɗannan ƙa'idodin ba su da cikakkiyar jituwa. Duk da haka, ana iya haɗa na'urar SATA zuwa mai haɗin SAS, amma ba akasin haka ba. An tabbatar da dacewa tsakanin faifan SATA da yankin SAS ta amfani da SATA Tunneling Protocol (STP).

Sigar farko ta daidaitattun SAS-1 tana da bandwidth na 3 Gb / s, kuma mafi zamani, SAS-4, ya inganta wannan adadi da sau 7: 22,5 Gb / s.

PCIe

Peripheral Component Interconnect Express (PCI Express, PCIe) serial interface don canja wurin bayanai, wanda ya bayyana a cikin 2002. Intel ne ya fara ci gaban, kuma daga baya an canza shi zuwa wata ƙungiya ta musamman - Ƙungiyar Ƙwararrun Ƙwararru ta PCI.

Serial PCIe interface ba banda ba kuma ya zama ci gaba mai ma'ana na daidaitaccen PCI, wanda aka ƙera don haɗa katunan faɗaɗawa.

PCI Express ya bambanta da SATA da SAS. Ƙaddamarwar PCIe tana da adadin layukan da suka bambanta. Adadin layukan daidai suke da iko biyu kuma sun bambanta daga 1 zuwa 16.

Kalmar "layin" a cikin PCIe baya nufin takamaiman layin sigina, amma zuwa wata hanyar sadarwa mai cikakken-duplex wacce ta ƙunshi hanyoyin sigina masu zuwa:

• karba+ da karɓa-;
• watsa + da watsawa-;
• hudu kasa wayoyi.

Adadin hanyoyin PCIe kai tsaye yana rinjayar iyakar bandwidth na haɗin kai. Ma'aunin PCI Express 4.0 na yanzu yana ba ku damar cimma 1.9 GB / s akan layi ɗaya, da 31.5 GB / s lokacin amfani da layin 16.

“Abincin abinci” na tuƙi mai ƙarfi-jihar yana girma da sauri. Dukansu SATA da SAS ba su sami damar haɓaka bandwidth don ci gaba da tafiya tare da SSDs ba, wanda ya haifar da ƙaddamar da SSDs masu haɗin PCIe.

Ko da yake PCIe Add-In katunan an dunƙule a kan, PCIe ne zafi swappable. Short fil PRSNT (Turanci na yanzu - yanzu) tabbatar da cewa an shigar da katin cikakke a cikin ramin.

Matsakaicin abubuwan tafiyar da jihar da aka haɗa ta PCIe ana sarrafa su ta wani ma'auni daban Ƙayyadaddun Interface Mai Rarraba Mai Rarraba Ƙwaƙwalwar Ƙwaƙwalwar Ƙwaƙwalwa kuma suna kunshe a cikin nau'i-nau'i iri-iri, amma za mu yi magana game da su a kashi na gaba.

Motoci masu nisa

Lokacin ƙirƙirar manyan ɗakunan ajiya na bayanai, akwai buƙatar ƙa'idodi waɗanda ke ba ku damar haɗa tutocin da ke wajen uwar garken. Magani na farko a wannan yanki shine Intanet SCSI (iSCSI), wanda IBM da Cisco suka haɓaka a cikin 1998.

Tunanin da ke bayan ka'idar iSCSI abu ne mai sauƙi: umarnin SCSI ana "nannade" cikin fakitin TCP/IP kuma a aika zuwa cibiyar sadarwa. Duk da haɗin nesa, yana ba abokan ciniki ra'ayi cewa an haɗa drive ɗin a gida. Wurin Yanar Gizon Ma'aji (SAN), bisa iSCSI, ana iya gina shi akan ababen more rayuwa na cibiyar sadarwa. Amfani da iSCSI yana rage farashin shirya SAN sosai.

iSCSI yana da zaɓi na "premium" - Ka'idar Tashar Fiber (FCP). SAN ta amfani da FCP an gina shi akan hanyoyin sadarwa na fiber-optic. Wannan tsarin yana buƙatar ƙarin kayan aikin cibiyar sadarwa na gani, amma yana da tsayayye kuma babban kayan aiki.

Akwai ka'idoji da yawa don aika umarnin SCSI akan cibiyoyin sadarwar kwamfuta. Koyaya, akwai ma'auni guda ɗaya kawai wanda ke magance akasin matsalar kuma yana ba ku damar aika fakitin IP akan bas ɗin SCSI - IP akan SCSI.

Yawancin ka'idojin SAN suna amfani da saitin umarni na SCSI don sarrafa abubuwan tafiyarwa, amma akwai keɓancewa, kamar masu sauƙi. ATA akan Ethernet (AOE). Ka'idar AoE tana aika umarnin ATA a cikin fakitin Ethernet, amma fakitin suna bayyana azaman SCSI a cikin tsarin.

Tare da zuwan faifan NVM Express, ƙa'idodin iSCSI da FCP sun daina cika buƙatun girma na SSDs. Magani guda biyu sun fito:

• cire bas ɗin PCI Express a wajen uwar garken;
• Ƙirƙirar NVMe akan Yarjejeniyar Fabrics.

Cire bas ɗin PCIe yana haifar da hadaddun kayan aikin sauyawa amma baya canza ƙa'idar.

NVMe akan Yarjejeniyar Fabrics ta zama kyakkyawan madadin iSCSI da FCP. NVMe-oF yana amfani da hanyar haɗin fiber optic da saitin umarnin NVM Express.

DDR-T

Matsayin iSCSI da NVMe-oF suna magance matsalar haɗa faifai masu nisa azaman na gida, yayin da Intel ya bi ta wata hanya kuma ya kawo na'urar cikin gida kusa da mai sarrafawa. Zaɓin ya faɗi akan ramukan DIMM waɗanda aka haɗa RAM a ciki. Matsakaicin bandwidth DDR4 shine 25 GB/s, wanda yayi sauri fiye da bas ɗin PCIe. Wannan shine yadda aka haifi Intel® Optane™ DC na dindindin Memory SSD.

An ƙirƙira wata yarjejeniya don haɗa tuƙi zuwa ramukan DIMM DDR-T, mai dacewa da jiki da lantarki tare da DDR4, amma yana buƙatar mai sarrafawa na musamman wanda ke ganin bambanci tsakanin ma'aunin ƙwaƙwalwar ajiya da abin tuƙi. Gudun samun damar zuwa tuƙi bai kai ga RAM ba, amma ya fi zuwa NVMe.

DDR-T yana samuwa ne kawai tare da Intel® Cascade Lake processor processor ko kuma daga baya.

ƙarshe

Kusan duk musaya sun yi nisa daga serial zuwa layi daya da watsa bayanai. Gudun SSD yana haɓakawa, jiya SSDs sun kasance abin sha'awa, kuma a yau NVMe ba abin mamaki bane.

A cikin dakin gwaje-gwajenmu Zaɓi Lab za ka iya gwada SSD da NVMe tafiyar da kanka.

Masu amfani da rajista kawai za su iya shiga cikin binciken. Shigadon Allah.

Shin direbobin NVMe zasu maye gurbin SSDs na yau da kullun a nan gaba?

• 55.5%Da 100

• 44.4%No80

Masu amfani 180 sun kada kuri'a. Masu amfani 28 sun kaurace.

source: www.habr.com