Extents yog txuas txuas rau ntawm lub hard disk uas siv los khaws cov ntaub ntawv nyob sib ze thiab tiv thaiv kev tawg. Fragments tshwm sim thaum ib feem ntawm cov ntaub ntawv tau tawg thoob plaws hauv lub hard disk thiab tsis muaj nyob hauv cov blocks sib txuas.
LVM yog dab tsi?
LVM rhuav tshem txhua qhov ntim ntawm lub cev mus rau ntau qhov. Ib lub logic ntim muaj ib txheej ntawm kev nthuav dav. Txhua qhov twg yog qhov tsis siv tag nrho, lossis siv tag nrho los ntawm ib qho kev xav tau tshwj xeeb: cov ntawv tsis tuaj yeem faib ua ntu. Extents yog the elementary blocks of LVM allocation.
Dab tsi yog nyob rau hauv Ext4?
Extents hloov cov txheej txheem thaiv daim phiaj siv los ntawm ext2 thiab ext3. Ib qhov twg yog qhov sib txuas ntawm lub cev sib txuas, txhim kho cov ntaub ntawv loj thiab txo cov fragmentation. Ib qhov twg hauv ext4 tuaj yeem qhia txog 128 MiB ntawm qhov chaw sib txuas nrog 4 KiB thaiv qhov loj.
Dab tsi yog qhov twg hauv cov ntaub ntawv kaw lus?
Hauv kev suav, ib feem yog thaj chaw sib txuas ntawm qhov chaw khaws cia rau cov ntaub ntawv hauv cov ntaub ntawv, sawv cev raws li ntau tus lej thaiv, lossis taug qab ntawm suav cov ntaub ntawv tseem ceeb. Cov ntaub ntawv tuaj yeem suav nrog xoom lossis ntau dua; ib cov ntaub ntawv fragment yuav tsum tau ib qhov twg.
Yuav ua li cas hauv Btrfs?
Btrfs qhov twg ntoo yog npaj los faib cov khoom muaj nyob rau hauv ntau txoj cai faib hloov pauv hloov pauv. Txhua qhov ntoo muaj ib ntu ntawm cov hauv paus disk, thiab lawv tuaj yeem muab rauib qho kev sau ntawm (los yog ib qho) tsob ntoo hauv paus, cov npe lossis inodes.
