Sabunta lokaci yana rinjayar aikin tsarin. Abin da ke faruwa a can da abin da za a yi game da shi - karanta labarin.
Duk lokacin da na sabunta Linux akan kwamfutar gida ta, dole ne in magance wasu matsaloli. A cikin shekaru da yawa, wannan ya zama al'ada: Ina adana fayiloli na, goge tsarin, shigar da komai daga karce, mayar da fayiloli na, sannan in sake shigar da aikace-aikacen da na fi so. Ina kuma canza saitunan tsarin don dacewa da kaina. Wani lokaci yana ɗaukar lokaci mai yawa. Kuma kwanan nan na yi mamakin ko ina buƙatar wannan ciwon kai.
lokaci shine ɗayan lokuta uku don fayiloli a cikin Linux (ƙari akan wannan daga baya). Musamman ma, ina mamakin ko har yanzu zai zama kyakkyawan ra'ayi don kashe atime akan ƙarin tsarin Linux na kwanan nan. Tun da an sabunta atime a duk lokacin da aka shiga fayil ɗin, na gane cewa yana da tasiri mai mahimmanci akan aikin tsarin.
Kwanan nan na haɓaka zuwa Fedora 32 kuma, daga al'ada, na fara da kashe atime. Na yi tunani: shin da gaske nake bukata? Na yanke shawarar yin nazarin wannan batu kuma wannan shine abin da na tono.
Kadan game da tamburan lokaci na fayil
Don gano shi, kuna buƙatar ɗaukar mataki baya kuma ku tuna wasu ƴan abubuwa game da tsarin fayil ɗin Linux da yadda kernel timestamps fayiloli da kundayen adireshi. Kuna iya ganin kwanan watan da aka gyara na fayiloli da kundayen adireshi ta hanyar gudanar da umarni ls -l (dogon) ko kuma kawai ta hanyar duba bayanai game da shi a cikin mai sarrafa fayil. Amma a bayan al'amuran, Linux kernel yana lura da tambura sau da yawa don fayiloli da kundayen adireshi:
- Yaushe ne aka gyara fayil ɗin ƙarshe (mtime)
- Yaushe ne lokaci na ƙarshe da aka canza kaddarorin fayil da metadata (lokaci)
- Yaushe ne aka fara isa ga fayil ɗin ƙarshe (lokaci)
- Kuna iya amfani da umarnin jihardon duba bayanai game da fayil ko kundin adireshi. Ga fayil ɗin / sauransu / fstab daga ɗaya daga cikin sabar gwaji na:
$ stat fstab
File: fstab
Size: 261 Blocks: 8 IO Block: 4096 regular file
Device: b303h/45827d Inode: 2097285 Links: 1
Access: (0664/-rw-rw-r--) Uid: ( 0/ root) Gid: ( 0/ root)
Context: system_u:object_r:etc_t:s0
Access: 2019-04-25 21:10:18.083325111 -0500
Modify: 2019-05-16 10:46:47.427686706 -0500
Change: 2019-05-16 10:46:47.434686674 -0500
Birth: 2019-04-25 21:03:11.840496275 -0500Anan za ku ga cewa an ƙirƙiri wannan fayil ɗin a ranar 25 ga Afrilu, 2019 lokacin da na shigar da tsarin. Fayil nawa / sauransu / fstab An sabunta ta ƙarshe a ranar 16 ga Mayu, 2019, kuma an canza duk wasu halaye a lokaci guda.
Idan na kwafa / sauransu / fstab zuwa sabon fayil, kwanakin suna canzawa don nuna cewa sabon fayil ne:
$ sudo cp fstab fstab.bak
$ stat fstab.bak
File: fstab.bak
Size: 261 Blocks: 8 IO Block: 4096 regular file
Device: b303h/45827d Inode: 2105664 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Context: unconfined_u:object_r:etc_t:s0
Access: 2020-05-12 17:53:58.442659986 -0500
Modify: 2020-05-12 17:53:58.443659981 -0500
Change: 2020-05-12 17:53:58.443659981 -0500
Birth: 2020-05-12 17:53:58.442659986 -0500Amma idan kawai na sake suna fayil ɗin ba tare da canza abinda ke ciki ba, Linux kawai za ta sabunta lokacin da aka canza fayil ɗin:
$ sudo mv fstab.bak fstab.tmp
$ stat fstab.tmp
File: fstab.tmp
Size: 261 Blocks: 8 IO Block: 4096 regular file
Device: b303h/45827d Inode: 2105664 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Context: unconfined_u:object_r:etc_t:s0
Access: 2020-05-12 17:53:58.442659986 -0500
Modify: 2020-05-12 17:53:58.443659981 -0500
Change: 2020-05-12 17:54:24.576508232 -0500
Birth: 2020-05-12 17:53:58.442659986 -0500Waɗannan tambarin lokutan suna da amfani sosai ga wasu shirye-shiryen Unix. Misali, biff shiri ne da ke sanar da kai lokacin da sabon sako ke cikin imel. A zamanin yau mutane kaɗan ne ke amfani da su , amma a zamanin da akwatunan wasiku sun kasance na gida ga tsarin, biff ya zama ruwan dare gama gari.
Ta yaya shirin zai san idan kana da sabon saƙo a cikin akwatin saƙo naka? biff yana kwatanta lokacin da aka gyara na ƙarshe (lokacin da aka sabunta fayil ɗin akwatin saƙo mai shiga tare da sabon saƙon imel) da lokacin samun damar ƙarshe (lokacin ƙarshe da kuka karanta imel ɗin ku). Idan canjin ya faru a baya fiye da samun dama, to biff zai fahimci cewa sabon wasiƙa ya zo kuma zai sanar da ku game da shi. Abokin imel ɗin Mutt yana aiki ta hanya ɗaya.
Tambarin lokutan samun dama na ƙarshe yana da amfani idan kuna buƙatar tattara kididdigar amfani da tsarin fayil da kunna aikin. Masu gudanar da tsarin suna buƙatar sanin abubuwan da ake shiga don su iya daidaita tsarin fayil daidai.
Amma yawancin shirye-shiryen zamani ba sa buƙatar wannan lakabin, don haka akwai shawarar kada a yi amfani da shi. A cikin 2007, Linus Torvalds da wasu masu haɓaka kernel da yawa sun tattauna atime a cikin mahallin matsalar aiki. Mai haɓaka kernel Linux Ingo Molnar ya yi magana mai zuwa game da atime da tsarin fayil na ext3:
"Abin ban mamaki ne cewa kowane tebur na Linux da uwar garken suna fama da lalacewar aikin I / O saboda ci gaba da sabunta lokaci, kodayake akwai masu amfani da gaske guda biyu kawai: tmpwatch [wanda za'a iya saita shi don amfani da ctime, don haka ba babbar matsala bane] kuma wasu kayan aikin ajiya."
Amma har yanzu mutane suna amfani da wasu shirye-shiryen da ke buƙatar wannan alamar. Don haka cire atime zai karya aikin su. Masu haɓaka kernel na Linux bai kamata su keta 'yancin mai amfani ba.
Maganin Sulaiman
Akwai aikace-aikace da yawa da aka haɗa a cikin rarraba Linux kuma ƙari, masu amfani za su iya saukewa da shigar da wasu shirye-shirye bisa ga bukatun su. Wannan babbar fa'ida ce ta buɗaɗɗen tushen OS. Amma wannan yana da wahala a inganta aikin tsarin fayil ɗin ku. Cire abubuwan da suka dace da albarkatu na iya rushe tsarin.
A matsayin sasantawa, masu haɓaka kernel na Linux sun gabatar da sabon zaɓin relaytime wanda aka yi niyya don daidaita daidaito tsakanin aiki da dacewa:
atime ana sabunta shi ne kawai idan lokacin samun damar da ya gabata ya kasa da na yanzu gyare-gyare ko lokacin canjin matsayi... Tun da Linux 2.6.30, kernel yana amfani da wannan zaɓi ta tsohuwa (sai dai idan an ƙayyade noatime)… Hakanan, tun Linux 2.6.30 . 1, lokacin samun damar ƙarshe na fayil koyaushe ana sabunta shi idan ya wuce kwana XNUMX.
Tsarin Linux na zamani (tun Linux 2.6.30, wanda aka saki a cikin 2009) sun riga sun yi amfani da lokacin relaytime, wanda yakamata ya ba da babban haɓakar aiki sosai. Wannan yana nufin ba kwa buƙatar saita fayil ɗin / sauransu / fstab, kuma tare da relaytime zaka iya dogara da tsoho.
Inganta aikin tsarin tare da noatime
Amma idan kuna son daidaita tsarin ku don samun mafi girman aiki, kashe atime har yanzu yana yiwuwa.
Canjin aikin ƙila ba zai zama sananne sosai akan faifai na zamani masu sauri ba (kamar NVME ko Fast SSD), amma akwai ƙaramin haɓaka a wurin.
Idan kun san ba ku amfani da software da ke buƙatar atime, zaku iya haɓaka aiki kaɗan ta kunna zaɓin noatime a cikin fayil ɗin. /etc/fstab. Bayan wannan, kwaya ba zai sabunta lokaci da lokaci ba. Yi amfani da zaɓin noatime lokacin hawan tsarin fayil:
/dev/mapper/fedora_localhost--live-root / ext4 defaults,noatime,x-systemd.device-timeout=0 1 1
UUID=be37c451-915e-4355-95c4-654729cf662a /boot ext4 defaults,noatime 1 2
UUID=C594-12B1 /boot/efi vfat umask=0077,shortname=winnt 0 2
/dev/mapper/fedora_localhost--live-home /home ext4 defaults,noatime,x-systemd.device-timeout=0 1 2
/dev/mapper/fedora_localhost--live-swap none swap defaults,x-systemd.device-timeout=0 0 0Canje-canjen za su yi tasiri a gaba lokacin da kuka sake yi.
Hakoki na Talla
Kuna buƙatar uwar garken don ɗaukar nauyin gidan yanar gizon ku? Kamfaninmu yana bayarwa tare da biyan kuɗi na yau da kullun ko lokaci ɗaya, kowane uwar garken yana haɗa zuwa tashar Intanet na 500 Megabits kuma ana kiyaye shi daga harin DDoS kyauta!
source: www.habr.com