Chidziwitso cha SSD. Gawo 2. Chiyankhulo

В gawo lomaliza M'ndandanda wa "Introduction to SSD", tinakambirana za mbiri ya maonekedwe a disks. Gawo lachiwiri lidzalankhula za mawonekedwe olumikizirana ndi ma drive.

Kulankhulana pakati pa purosesa ndi zida zotumphukira kumachitika molingana ndi zomwe zidafotokozedwatu zomwe zimatchedwa ma interfaces. Mapanganowa amawongolera kuchuluka kwa machitidwe ndi mapulogalamu.

Chiyankhulo ndi zida, njira ndi malamulo olumikizirana pakati pa zinthu zamadongosolo.

Kukhazikitsa kwakuthupi kwa mawonekedwe kumakhudza magawo awa:

• kuthekera kwa njira yolumikizirana;
• kuchuluka kwa zida zolumikizidwa nthawi imodzi;
• kuchuluka kwa zolakwika zomwe zimachitika.

Ma Disk interfaces amapangidwa Madoko a I/O, zomwe ndizosiyana ndi kukumbukira I/O ndipo sizitenga malo mu adilesi ya purosesa.

Parallel ndi siriyo madoko

Malinga ndi njira yosinthira deta, madoko a I/O amagawidwa m'mitundu iwiri:

• kufanana;
• mosasinthasintha.

Monga momwe dzinalo likusonyezera, doko lofananira limatumiza mawu amakina okhala ndi ma bits angapo nthawi imodzi. Doko lofananira ndi njira yosavuta yosinthira deta, chifukwa sichifuna mayankho ovuta ozungulira. Munthawi yosavuta, mawu aliwonse amakina amatumizidwa pamzere wake wamakina, ndipo mizere iwiri yazizindikiro imagwiritsidwa ntchito poyankha: Deta yakonzeka и Zomwe zavomerezedwa.

Madoko ofanana amawoneka kuti akukula bwino poyang'ana koyamba: mizere yowonjezereka imatanthawuza kuti ma bits ambiri amasamutsidwa panthawi imodzi, motero, kutulutsa kwakukulu. Komabe, chifukwa cha kuchuluka kwa mizere yazizindikiro, kusokoneza kumachitika pakati pawo, zomwe zimapangitsa kusokoneza mauthenga omwe amafalitsidwa.

Ma serial ports ndi osiyana ndi ma doko ofanana. Deta imatumizidwa pang'onopang'ono, zomwe zimachepetsa chiwerengero cha mizere yowonetsera koma zimawonjezera zovuta kwa wolamulira wa I / O. Woyang'anira ma transmitter amalandira mawu pamakina nthawi imodzi ndipo amayenera kutumiza pang'ono pang'ono, ndipo wowongolera wolandila nayenso ayenera kulandira ma bits ndikusunga mu dongosolo lomwelo.

Chiwerengero chochepa cha mizere yazizindikiro chimakulolani kuti muwonjezere maulendo otumizira mauthenga popanda kusokoneza.

SCSI

Small Computer Systems Interface (SCSI) idawonekera kale mu 1978 ndipo idapangidwa kuti iziphatikiza zida zamitundu yosiyanasiyana kukhala dongosolo limodzi. Mafotokozedwe a SCSI-1 amaperekedwa kuti alumikizane ndi zida 8 (pamodzi ndi wowongolera), monga:

• scanner;
• zoyendetsa tepi (mitsinje);
• ma drive a Optical;
• ma drive a disk ndi zida zina.

SCSI poyamba inkatchedwa Shugart Associates System Interface (SASI), koma komiti ya miyezo sinavomereze dzinalo pambuyo pa kampaniyo, ndipo patatha tsiku la kulingalira, dzina lakuti Small Computer Systems Interface (SCSI) linabadwa. "Bambo" a SCSI, a Larry Boucher, adafuna kuti mawuwa atchulidwe kuti "chigololo", koma Ndi Allan Ndinawerenga mawu akuti “scuzzy” (“ndiuze”). Pambuyo pake, matchulidwe a "skazi" adaperekedwa mokhazikika ku muyezo uwu.

Mu terminology ya SCSI, zida zolumikizidwa zimagawidwa m'mitundu iwiri:

• oyambitsa;
• zida chandamale.

Woyambitsayo amatumiza lamulo ku chipangizo chandamale, chomwe chimatumiza yankho kwa woyambitsa. Oyambitsa ndi zolinga amalumikizidwa ndi basi wamba ya SCSI, yomwe ili ndi bandwidth ya 1 MB / s muyeso wa SCSI-5.

"Mabasi wamba" omwe amagwiritsidwa ntchito amaika ziletso zingapo:

• Pamapeto a basi, zida zapadera zimafunikira - zotsekera;
• Bandwidth ya basi imagawidwa pakati pa zida zonse;
• Chiwerengero chachikulu cha zida zolumikizidwa nthawi imodzi ndizochepa.

Zida zomwe zili m'basi zimadziwika ndi nambala yapadera yotchedwa SCSI Target ID. Chigawo chilichonse cha SCSI mudongosolo chimayimiridwa ndi chipangizo chimodzi chomveka, chomwe chimayankhidwa pogwiritsa ntchito nambala yapadera mkati mwa chipangizocho. Nambala Yachigawo Yomveka (LUN).

Malamulo a SCSI amatumizidwa ngati midadada yofotokozera malamulo (Command Descriptor Block, CDB), yopangidwa ndi code code ndi malamulo magawo. Muyezowu umafotokoza malamulo opitilira 200, ogawidwa m'magulu anayi:

• kuvomerezedwa - ayenera kuthandizidwa ndi chipangizo;
• unsankhula - akhoza kukhazikitsidwa;
• Wogulitsa mwachindunji - amagwiritsidwa ntchito ndi wopanga wina;
• Zatha - malamulo akale.

Mwa malamulo ambiri, atatu okha a iwo ali ovomerezeka pazida:

• ZOYESA ZOPHUNZITSA - kuyang'ana kukonzekera kwa chipangizocho;
• PEMBANI MFUNDO - imapempha nambala yolakwika ya lamulo lakale;
• Kufufuza - pempho la zofunikira za chipangizocho.

Pambuyo polandira ndi kuchita lamulo, chipangizo chandamale chimatumiza woyambitsa ndondomeko yomwe imalongosola zotsatira za kuphedwa.

Kuwongolera kwina kwa SCSI (SCSI-2 ndi Ultra SCSI specifications) kunakulitsa mndandanda wamalamulo omwe amagwiritsidwa ntchito ndikuwonjezera kuchuluka kwa zida zolumikizidwa mpaka 16, komanso liwiro la kusinthana kwa data pabasi mpaka 640 MB/s. Popeza SCSI ndi mawonekedwe ofanana, kuwonjezereka kwafupipafupi kusinthanitsa deta kunagwirizanitsidwa ndi kuchepa kwa kutalika kwa chingwe chazitali ndipo kunayambitsa kusokoneza ntchito.

Kuyambira ndi muyezo wa Ultra-3 SCSI, chithandizo cha "plugging yotentha" chinawonekera - zida zolumikizira pomwe magetsi ali.

Ma SSD odziwika omwe ali ndi mawonekedwe a SCSI amatha kuonedwa ngati M-Systems FFD-350, yomwe idatulutsidwa mu 1995. Diskiyo inali yokwera mtengo ndipo sinali yofala.

Pakadali pano, SCSI yofananira si njira yolumikizira disk yodziwika bwino, koma lamulo lokhazikitsidwa likugwiritsidwabe ntchito mwachangu pamayendedwe a USB ndi SAS.

ATA/PATA

mawonekedwe ATA (Advanced Technology Attachment), yomwe imadziwikanso kuti PAW (Parallel ATA) idapangidwa ndi Western Digital mu 1986. Dzina la malonda la IDE standard (Integrated Drive Electronics) linagogomezera luso lofunika kwambiri: woyendetsa galimotoyo anamangidwa mu galimoto, osati pa bolodi yowonjezera yowonjezera.

Chisankho choyika chowongolera mkati mwagalimoto chinathetsa mavuto angapo nthawi imodzi. Choyamba, mtunda kuchokera pagalimoto kupita kwa wowongolera watsika, womwe umakhala ndi zotsatira zabwino pamakhalidwe agalimoto. Kachiwiri, woyang'anira womangidwa "adakonzedwa" kokha pamtundu wina wa galimoto ndipo, motero, anali wotsika mtengo.

ATA, monga SCSI, imagwiritsa ntchito njira yofanana ya I / O, yomwe imakhudza zingwe zomwe zimagwiritsidwa ntchito. Kulumikiza ma drive pogwiritsa ntchito mawonekedwe a IDE, zingwe zamawaya 40, zomwe zimatchedwanso zingwe, zimafunikira. Zolemba zaposachedwa zimagwiritsa ntchito malupu 80-waya: opitilira theka omwe ndi zifukwa zochepetsera kusokoneza pama frequency apamwamba.

Chingwe cha ATA chimakhala ndi zolumikizira ziwiri mpaka zinayi, imodzi yomwe imalumikizidwa ndi bolodi la mama, ndipo ena onse amayendetsa. Mukalumikiza zida ziwiri ndi chingwe chimodzi, chimodzi mwazo chiyenera kukhazikitsidwa ngati Master, ndi chachiwiri - monga Kapolo. Chipangizo chachitatu chitha kulumikizidwa powerenga pokha.

Malo a jumper amatanthawuza ntchito ya chipangizo china. Mawu akuti Mbuye ndi Kapolo pokhudzana ndi zida sizolondola kwenikweni, chifukwa pokhudzana ndi wowongolera zida zonse zolumikizidwa ndi Akapolo.

Kupanga kwapadera mu ATA-3 ndiko mawonekedwe Kudziyang'anira, Analysis and Reporting Technology (SMART). Makampani asanu (IBM, Seagate, Quantum, Conner ndi Western Digital) agwirizana ndi ukadaulo wokhazikika pakuwunika thanzi la ma drive.

Thandizo la ma drive a solid-state adawonekera ndi mtundu wachinayi wa muyezo, womwe unatulutsidwa mu 1998. Mtundu uwu wazomwe zimaperekedwa ndi liwiro losamutsa deta mpaka 33.3 MB/s.

Muyezowu umayika patsogolo zofunikira pazingwe za ATA:

• sitimayo iyenera kukhala yosalala;
• kutalika kwa sitimayi ndi mainchesi 18 (masentimita 45.7).

Sitima yaifupi ndi yotakata inali yovuta ndipo inasokoneza kuziziritsa. Zinakhala zovuta kuonjezera mafupipafupi opatsirana ndi mtundu uliwonse wotsatira wa muyezo, ndipo ATA-7 inathetsa vutoli kwambiri: mawonekedwe ofanana adasinthidwa ndi serial. Zitatha izi, ATA idapeza mawu akuti Parallel ndipo idadziwika kuti PATA, ndipo mtundu wachisanu ndi chiwiri wa muyezo unalandira dzina losiyana - seri ATA. Kuwerengera kwa mitundu ya SATA kunayambira pa imodzi.

SATA

Muyezo wa Serial ATA (SATA) udayambitsidwa pa Januware 7, 2003 ndikuthana ndi zovuta zomwe zidalipo kale ndi zosintha zotsatirazi:

• doko lofanana lasinthidwa ndi serial imodzi;
• chingwe chachikulu cha mawaya 80 chimasinthidwa ndi waya 7;
• Topology ya "common bus" yasinthidwa ndi "point-to-point".

Ngakhale kuti muyezo wa SATA 1.0 (SATA/150, 150 MB/s) unali wothamanga pang'ono kuposa ATA-6 (UltraDMA/130, 130 MB/s), kusintha kwa njira yosinthira deta "kunakonzekeretsa nthaka" liwiro lowonjezeka

Mizere khumi ndi isanu ndi umodzi yotumizira deta mu ATA inasinthidwa ndi awiriawiri opotoka: imodzi yotumiza, ina yolandira. Zolumikizira za SATA zidapangidwa kuti zikhale zolimba pakulumikizananso kangapo, ndipo mawonekedwe a SATA 1.0 adapangitsa Hot Plug kukhala yotheka.

Zikhomo zina pa disk ndi zazifupi kuposa zina zonse. Izi zachitika kuthandizira Kusinthana kwa Hot. Panthawi yosinthira, chipangizocho "chimatayika" ndi "kupeza" mizere mwadongosolo lokonzedweratu.

Patangotha ​​chaka chimodzi, mu April 2004, mtundu wachiwiri wa ndondomeko ya SATA unatulutsidwa. Kuphatikiza pa kuthamangitsa mpaka 3 Gbit/s, SATA 2.0 idayambitsa ukadaulo Native Command Queuing (NCQ). Zipangizo zokhala ndi chithandizo cha NCQ zimatha kudziyimira pawokha momwe malamulo olandirira amagwirira ntchito kuti akwaniritse ntchito yayikulu.

Kwa zaka zitatu zotsatira, Gulu Logwira Ntchito la SATA linagwira ntchito yokonza ndondomeko yomwe inalipo kale ndipo mu version 2.6 compact Slimline ndi micro SATA (uSATA) zolumikizira zidawonekera. Zolumikizira izi ndi mtundu wawung'ono wa cholumikizira choyambirira cha SATA ndipo amapangidwira ma drive owoneka bwino ndi ma drive ang'onoang'ono pama laputopu.

Ngakhale m'badwo wachiwiri wa SATA unali ndi bandwidth yokwanira pa hard drive, ma SSD amafunikira zambiri. Mu Meyi 2009, mtundu wachitatu wa SATA udatulutsidwa ndikuwonjezeka kwa bandwidth mpaka 6 Gbit/s.

Chisamaliro chapadera chidaperekedwa kumayendedwe olimba amtundu wa SATA 3.1. Cholumikizira cha Mini-SATA (mSATA) chawonekera, chopangidwira kulumikiza ma drive olimba mu laputopu. Mosiyana ndi Slimline ndi SATA, cholumikizira chatsopanocho chinali chofanana ndi PCIe Mini, ngakhale sichinali chogwirizana ndi PCIe pamagetsi. Kuphatikiza pa cholumikizira chatsopano, SATA 3.1 idadzitamandira kuti imatha kuyika malamulo a TRIM ndi malamulo owerengera ndi kulemba.

Lamulo la TRIM limadziwitsa SSD za midadada ya data yomwe ilibe katundu. Pamaso pa SATA 3.1, kuchita lamuloli kungapangitse kuti ma cache asungunuke ndipo I/O idzayimitsidwa, ndikutsatiridwa ndi lamulo la TRIM. Njira iyi idasokoneza magwiridwe antchito a disk panthawi yochotsa.

Mafotokozedwe a SATA sakanatha kuyenderana ndi kukula kwachangu kwa liwiro lofikira pamagalimoto olimba, zomwe zidapangitsa kuti mu 2013 kuwoneka kwachinyengo chotchedwa SATA Express mu SATA 3.2 standard. M'malo mowirikiza kawiri bandwidth ya SATA kachiwiri, opanga adagwiritsa ntchito basi ya PCIe yomwe imagwiritsidwa ntchito kwambiri, yomwe liwiro lake limaposa 6 Gbps. Ma Drives othandizira SATA Express apeza mawonekedwe awoawo otchedwa M.2.

SAS

Muyezo wa SCSI, "kupikisana" ndi ATA, nawonso sunayime ndipo patangopita chaka chimodzi kuchokera pakuwonekera kwa seri ATA, mu 2004, idabadwanso ngati mawonekedwe a serial. Dzina la mawonekedwe atsopano ndi Seri Yophatikizidwa ndi SCSI (SEJI).

Ngakhale kuti SAS idalandira lamulo la SCSI, zosinthazo zinali zofunika:

• serial mawonekedwe;
• 29-waya chingwe mphamvu;
• kugwirizana kwa mfundo ndi mfundo

Mawu akuti SCSI adatengeranso cholowa. Wowongolera amatchedwabe woyambitsa, ndipo zida zolumikizidwa zimatchedwabe chandamale. Zida zonse zomwe zimayang'aniridwa ndi woyambitsa amapanga dera la SAS. Ku SAS, kulumikizana sikudalira kuchuluka kwa zida zomwe zili mu domain, popeza chipangizo chilichonse chimagwiritsa ntchito njira yake yodzipatulira.

Kuchuluka kwa zida zolumikizidwa nthawi imodzi mugawo la SAS molingana ndi zomwe zafotokozedwa zimaposa 16, ndipo m'malo mwa ID ya SCSI, chizindikiritso chimagwiritsidwa ntchito poyankhulira. Dzina Lapadziko Lonse (WWN).

WWN ndi chizindikiritso chapadera cha 16 byte kutalika, chofanana ndi adilesi ya MAC ya zida za SAS.

Ngakhale kufanana kwa zolumikizira za SAS ndi SATA, miyezo iyi sagwirizana kwathunthu. Komabe, kuyendetsa kwa SATA kumatha kulumikizidwa ndi cholumikizira cha SAS, koma osati mosemphanitsa. Kugwirizana pakati pa ma drive a SATA ndi dera la SAS kumatsimikiziridwa pogwiritsa ntchito SATA Tunnel Protocol (STP).

Mtundu woyamba wa muyezo wa SAS-1 umakhala ndi 3 Gbit / s, ndipo wamakono kwambiri, SAS-4, wasintha chiwerengerochi ndi nthawi 7: 22,5 Gbit / s.

PCI

Peripheral Component Interconnect Express (PCI Express, PCIe) ndi mawonekedwe osamutsa osamutsa deta, omwe adawonekera mu 2002. Chitukuko chinayambitsidwa ndi Intel, ndipo kenako anasamutsidwa ku bungwe lapadera - PCI Special Interest Group.

Mawonekedwe a serial PCIe analinso chimodzimodzi ndipo adakhala kupitiliza koyenera kwa PCI yofananira, yomwe idapangidwira kulumikiza makhadi okulitsa.

PCI Express ndiyosiyana kwambiri ndi SATA ndi SAS. Mawonekedwe a PCIe ali ndi njira zingapo zosinthira. Chiwerengero cha mizere ndi chofanana ndi mphamvu ziwiri ndipo chimachokera ku 1 mpaka 16.

Mawu akuti "njira" mu PCIe samatanthawuza chingwe cha siginecha, koma njira imodzi yolumikizirana yokhazikika yokhala ndi mizere yotsatirayi:

• phwando + ndi kulandirira-;
• kutumiza + ndi kufalitsa-;
• ma conductor anayi oyambira.

Kuchuluka kwa misewu ya PCIe kumakhudza mwachindunji kuchuluka kwa kulumikizana. Muyezo wamakono wa PCI Express 4.0 umakupatsani mwayi wofikira 1.9 GB/s pamzere umodzi, ndi 31.5 GB/s mukamagwiritsa ntchito mizere 16.

Chilakolako cha ma drive a solid-state chikukula mwachangu kwambiri. Onse a SATA ndi SAS alibe nthawi yoti awonjezere bandwidth yawo kuti "akhalebe" ndi ma SSD, zomwe zidapangitsa kuti pakhale ma drive a SSD okhala ndi ma PCIe.

Ngakhale makhadi Owonjezera a PCIe amawomberedwa, PCIe ndi yotentha. Zikhomo zazifupi za PRSNT (Chingerezi zilipo - zomwe zilipo) zimakulolani kuti muwonetsetse kuti khadiyo yayikidwa kwathunthu mu slot.

Ma drive olimba olumikizidwa kudzera pa PCIe amayendetsedwa ndi mulingo wosiyana Kufotokozera kwa Mawonekedwe Osasinthika a Memory Host Controller ndipo ali muzinthu zosiyanasiyana, koma tidzakambirana mu gawo lotsatira.

Magalimoto akutali

Popanga malo osungiramo data akulu, pafunika ma protocol omwe amalola kulumikiza ma drive omwe ali kunja kwa seva. Njira yoyamba m'derali inali Mtengo SCSI pa intaneti (iSCSI), yopangidwa ndi IBM ndi Cisco mu 1998.

Lingaliro la protocol ya iSCSI ndi losavuta: malamulo a SCSI "akutidwa" m'mapaketi a TCP/IP ndikutumizidwa ku netiweki. Ngakhale kulumikizidwa kwakutali, chinyengo chimapangidwira makasitomala kuti galimotoyo imalumikizidwa kwanuko. ISCSI-based Storage Area Network (SAN) itha kumangidwa pamanetiweki omwe alipo. Kugwiritsa ntchito iSCSI kumachepetsa kwambiri mtengo wokonzekera SAN.

iSCSI ili ndi njira ya "premium" - Fiber Channel Protocol (FCP). SAN yogwiritsa ntchito FCP imamangidwa pamizere yolumikizana ndi fiber optic. Njirayi imafunikira zida zowonjezera zowonera pa netiweki, koma ndizokhazikika komanso zimakhala ndi zida zambiri.

Pali ma protocol ambiri otumizira SCSI malamulo pamanetiweki apakompyuta. Komabe, pali muyezo umodzi wokha womwe umathetsa vuto losiyana ndi kulola mapaketi a IP kutumizidwa pa basi ya SCSI - IP-over-SCSI.

Ma protocol ambiri a SAN amagwiritsa ntchito lamulo la SCSI kuti aziyendetsa ma drive, koma pali zina, monga zosavuta ATA pa Ethernet (AoE). Protocol ya AoE imatumiza malamulo a ATA m'mapaketi a Ethernet, koma ma drive amawoneka ngati SCSI mudongosolo.

Kubwera kwa ma drive a NVM Express, ma protocol a iSCSI ndi FCP sakukwaniritsanso zomwe zikukula mwachangu za SSD. Njira ziwiri zidawonekera:

• kusuntha basi ya PCI Express kunja kwa seva;
• kupanga NVMe over Fabrics protocol.

Kuchotsa basi ya PCIe kumaphatikizapo kupanga zida zosinthira zovuta, koma sizisintha protocol.

NVMe over Fabrics protocol yakhala njira yabwino kwa iSCSI ndi FCP. NVMe-oF imagwiritsa ntchito ulalo wa fiber optic ndi seti ya malangizo a NVM Express.

DDR-T

Miyezo ya iSCSI ndi NVMe-oF imathetsa vuto la kulumikiza ma disks akutali monga am'deralo, koma Intel anatenga njira yosiyana ndikubweretsa disk yakomweko pafupi ndi purosesa. Kusankha kudagwera pa DIMM slots momwe RAM imalumikizidwa. Kuthamanga kwakukulu kwa DDR4 channel ndi 25 GB / s, komwe kumakhala kokwera kwambiri kuposa kuthamanga kwa basi ya PCIe. Umu ndi momwe Intel® Optane™ DC Persistent Memory SSD idabadwa.

Protocol idapangidwa kuti ilumikize ma drive ku DIMM slots DDR-T, thupi ndi magetsi n'zogwirizana ndi DDR4, koma amafuna wolamulira wapadera amene amaona kusiyana kukumbukira ndodo ndi galimoto. Kuthamanga kwa galimoto kumakhala kocheperapo kuposa RAM, koma mofulumira kuposa NVMe.

DDR-T imapezeka ndi mapurosesa a Intel® Cascade Lake kapena mtsogolo.

Pomaliza

Pafupifupi ma interfaces onse achoka patali kuchokera panjira zosamutsa deta mpaka zofanana. Kuthamanga kwa SSD kukukula mofulumira; dzulo la SSD linali lachilendo, koma lero NVMe sichikudabwitsanso.

Mu labotale yathu Selectel Lab mutha kuyesa ma SSD ndi ma NVMe ma drive nokha.

Ogwiritsa ntchito olembetsedwa okha ndi omwe angatenge nawo gawo pa kafukufukuyu. Lowani muakauntichonde.

Kodi ma drive a NVMe adzalowa m'malo mwa ma SSD apamwamba posachedwa?

• 55.5%Yes100

• 44.4%No80

Ogwiritsa 180 adavota. Ogwiritsa ntchito 28 adakana.

Source: www.habr.com