Yadda ake Mai da Data da Sake Gina RAIDs na Software da ba a yi nasara ba - Part 8


A cikin labaran da suka gabata na wannan jerin RAID kun tashi daga sifili zuwa jaruma RAID. Mun sake duba tsarin RAID na software da yawa kuma mun bayyana mahimman abubuwan kowane ɗayan, tare da dalilan da yasa zaku karkata zuwa ɗayan ko ɗayan ya danganta da takamaiman yanayin ku.

A cikin wannan jagorar za mu tattauna yadda ake sake gina tsarin RAID na software ba tare da asarar bayanai ba lokacin da aka sami gazawar diski. Don taƙaitawa, za mu yi la'akari da saitin RAID 1 kawai - amma dabaru da umarni sun shafi kowane yanayi iri ɗaya.

Kafin a ci gaba, da fatan za a tabbatar cewa kun saita tsarin RAID 1 bin umarnin da aka bayar a Sashe na 3 na wannan jerin: Yadda ake saita RAID 1 (Mirror) a cikin Linux.

Bambance-bambancen da ke cikin yanayin mu na yanzu shine:

1) sigar daban ta CentOS (v7) fiye da wacce aka yi amfani da ita a waccan labarin (v6.5), da
2) Girman faifai daban-daban don /dev/sdb da /dev/sdc (8 GB kowanne).

Bugu da ƙari, idan an kunna SELinux a yanayin tilastawa, kuna buƙatar ƙara alamun da suka dace a cikin kundin adireshi inda za ku hau na'urar RAID. In ba haka ba, za ku ci karo da wannan saƙon gargaɗi yayin ƙoƙarin hawansa:

Kuna iya gyara wannan ta hanyar gudu:

# restorecon -R /mnt/raid1

Kafa RAID Kulawa

Akwai dalilai da yawa da ya sa na'urar ajiya zata iya kasawa (SSDs sun rage yawan damar faruwar hakan, ko da yake), amma ko da menene dalilin za ku iya tabbata cewa batutuwa na iya faruwa kowane lokaci kuma kuna buƙatar zama cikin shiri don maye gurbin gazawar. bangare kuma don tabbatar da samuwa da amincin bayanan ku.

Maganar nasiha tukuna. Ko da lokacin da za ku iya bincika /proc/mdstat don bincika matsayin RAIDs ɗinku, akwai hanya mafi kyau da adana lokaci wacce ta ƙunshi tafiyar da mdadm a yanayin duba +, wanda zai aika da faɗakarwa ta hanyar imel zuwa takamaiman mai karɓa.

Don saita wannan, ƙara layin mai zuwa a /etc/mdadm.conf:

MAILADDR [email <domain or localhost>

A wurina:

MAILADDR [email 

Don gudanar da mdadm a yanayin duba + duba, ƙara shigarwar crontab mai zuwa azaman tushen:

@reboot /sbin/mdadm --monitor --scan --oneshot

Ta hanyar tsoho, mdadm zai duba tsararrun RAID kowane sakan 60 kuma ya aika da faɗakarwa idan ya sami matsala. Kuna iya canza wannan hali ta ƙara zaɓin -- jinkirta zuwa shigarwar crontab a sama tare da adadin daƙiƙa (misali, -- jinkirta 1800 yana nufin minti 30).

A ƙarshe, tabbatar cewa an shigar da Wakilin Mai Amfani (MUA), kamar mutt ko mailx. In ba haka ba, ba za ku sami wani faɗakarwa ba.

A cikin minti daya zamu ga yadda faɗakarwar da mdadm ta aiko ta kasance.

Yin kwaikwayo da Sauya Na'urar Ma'ajiya ta RAID da ta gaza

Don kwatanta matsala tare da ɗaya daga cikin na'urorin ajiya a cikin tsararrun RAID, za mu yi amfani da zaɓuɓɓukan --manage da --set-faultyzaɓuɓɓukan kamar haka:

# mdadm --manage --set-faulty /dev/md0 /dev/sdc1  

Wannan zai haifar da alamar /dev/sdc1 a matsayin kuskure, kamar yadda muke iya gani a /proc/mdstat:

Mafi mahimmanci, bari mu ga idan mun sami faɗakarwar imel tare da gargaɗi iri ɗaya:

A wannan yanayin, kuna buƙatar cire na'urar daga tsararrun software na RAID:

# mdadm /dev/md0 --remove /dev/sdc1

Sa'an nan za ku iya cire shi ta jiki daga na'ura kuma ku maye gurbin shi da wani sashi (/ dev/sdd, inda aka ƙirƙiri wani bangare na nau'in fd):

# mdadm --manage /dev/md0 --add /dev/sdd1

An yi sa'a a gare mu, tsarin zai fara sake gina tsararru ta atomatik tare da ɓangaren da muka ƙara. Za mu iya gwada wannan ta yin alama /dev/sdb1 a matsayin kuskure, cire shi daga tsararru, da kuma tabbatar da cewa fayil ɗin tecmint.txt har yanzu yana samuwa a /mnt/raid1:

# mdadm --detail /dev/md0
# mount | grep raid1
# ls -l /mnt/raid1 | grep tecmint
# cat /mnt/raid1/tecmint.txt

Hoton da ke sama yana nuna a sarari cewa bayan ƙara/dev/sdd1 zuwa tsararru a matsayin maye gurbin/dev/sdc1, tsarin ya sake gina bayanai ta atomatik ba tare da tsoma baki daga bangarenmu ba.

Ko da yake ba a buƙata sosai ba, yana da kyau a sami na'urar da za a iya amfani da ita ta yadda za a iya yin aikin maye gurbin na'urar da ba ta da kyau da mota mai kyau a cikin tartsatsi. Don yin haka, bari mu sake ƙara /dev/sdb1 da /dev/sdc1:

# mdadm --manage /dev/md0 --add /dev/sdb1
# mdadm --manage /dev/md0 --add /dev/sdc1

Farfadowa daga Rasuwar Redundancy

Kamar yadda aka bayyana a baya, mdadm zai sake gina bayanan ta atomatik lokacin da diski ɗaya ya gaza. Amma menene zai faru idan 2 diski a cikin tsararru sun kasa? Bari mu kwaikwayi irin wannan yanayin ta hanyar yiwa /dev/sdb1 da /dev/sdd1 alama mara kyau:

# umount /mnt/raid1
# mdadm --manage --set-faulty /dev/md0 /dev/sdb1
# mdadm --stop /dev/md0
# mdadm --manage --set-faulty /dev/md0 /dev/sdd1

Ƙoƙarin sake ƙirƙira tsararrun kamar yadda aka ƙirƙira shi a wannan lokacin (ko amfani da zaɓin --assume-clean na iya haifar da asarar bayanai, don haka yakamata a bar shi azaman makoma ta ƙarshe.

Bari muyi kokarin dawo da bayanan daga/dev/sdb1, alal misali, cikin nau'in diski mai kama da (/ dev/sde1 - lura cewa wannan yana buƙatar ƙirƙirar ɓangaren nau'in fd a/dev/sde kafin ci gaba) ta amfani da ddrescue:

# ddrescue -r 2 /dev/sdb1 /dev/sde1

Lura cewa har zuwa wannan batu, ba mu taɓa /dev/sdb ko /dev/sdd ba, ɓangarori waɗanda ke cikin tsararrun RAID.

Yanzu bari mu sake gina tsararru ta amfani da /dev/sde1 da /dev/sdf1:

# mdadm --create /dev/md0 --level=mirror --raid-devices=2 /dev/sd[e-f]1

Lura cewa a halin da ake ciki, yawanci za ku yi amfani da sunayen na'urori iri ɗaya kamar na asali, wato, /dev/sdb1 da /dev/sdc1 bayan an maye gurbin faifan diski da sababbi.

A cikin wannan labarin na zaɓi yin amfani da ƙarin na'urori don sake ƙirƙira tsararru tare da sabbin fayafai da kuma guje wa rudani tare da faɗuwar faɗuwar asali.

Lokacin da aka tambaye ko za a ci gaba da rubuta tsararru, rubuta Y kuma latsa Shigar. Ya kamata a fara tsara tsarin kuma kuna iya kallon ci gabanta tare da:

# watch -n 1 cat /proc/mdstat

Lokacin da aikin ya ƙare, yakamata ku sami damar shiga cikin abubuwan da ke cikin RAID ɗin ku:

Takaitawa

A cikin wannan labarin mun sake nazarin yadda ake murmurewa daga gazawar RAID da asarar sakewa. Koyaya, kuna buƙatar tuna cewa wannan fasaha shine mafita ta ajiya kuma BA ta maye gurbin madadin ba.

Ka'idodin da aka bayyana a cikin wannan jagorar sun shafi duk saitin RAID iri ɗaya, da kuma ra'ayoyin da za mu rufe a jagora na gaba da na ƙarshe na wannan jerin (Gudanar da RAID).

Idan kuna da wasu tambayoyi game da wannan labarin, jin daɗi don sauke mana bayanin kula ta amfani da fom ɗin sharhi da ke ƙasa. Muna jiran ji daga gare ku!