【Linux】Linux command: lvcreate trick

Use the lvcreate commandCreate a logical volume of LVM。

A logical volume is created on a volume group, and the device files corresponding to the logical volume are saved in the volume group directory;

For example: create a logical volume "lv_1" on the volume group "vg_1", and the device file corresponding to this logical volume is "/dev/vg_1/lv_1".

grammar
lvcreate(option)(parameters)

Command description

[root@mwd ~]# lvcreate --help

lvcreate: Create a logical volume
lvcreate
[-A|--autobackup {y|n}] (autobackup)
        [-a|--activate [a|e|l]{y|n}]
[--addtag ​​Tag] (add tag)
[--alloc AllocationPolicy] (Assignment Policy)
[--cachemode CacheMode] (Cache mode)
        [-C|--contiguous {y|n}]
        [-d|--debug]
        [-h|-?|--help]
[--ignoremonitoring] (ignoremonitoring)
[--monitor {y|n}] (monitor)
        [-i|--stripes Stripes [-I|--stripesize StripeSize]]
        [-k|--setactivationskip {y|n}]
        [-K|--ignoreactivationskip]
        {-l|--extents LogicalExtentsNumber[%{VG|PVS|FREE}] | (Logical extension number)
         -L|--size LogicalVolumeSize[bBsSkKmMgGtTpPeE]} (logical volume size)
        [-M|--persistent {y|n}] [--major major] [--minor minor]
[-m|--mirrors Mirrors [--nosync] [{--mirrorlog {disk|core|mirrored}|--corelog}]] (mirrors)
        [-n|--name LogicalVolumeName] (logical volume name)
        [--noudevsync]
        [-p|--permission {r|rw}]
        [--[raid]minrecoveryrate Rate]
        [--[raid]maxrecoveryrate Rate]
[-r|--readahead ReadAheadSectors|auto|none] (read head sector)
[-R|--regionsize MirrorLogRegionSize] (mirror logic region size)
[-T|-thin [-c|--chunksize  ChunkSize] (block size)
          [--discards {ignore|nopassdown|passdown}]
          [--poolmetadatasize MetadataSize[bBsSkKmMgG]]]
          [--poolmetadataspare {y|n}]
[--thinpool ThinPoolLogicalVolume{Name|Path}] (Simplified pool logic volume)
        [-t|--test]
[--type VolumeType] (volume type)
        [-v|--verbose]
        [-W|--wipesignatures {y|n}]
        [-Z|--zero {y|n}]
        [--version]

        VolumeGroupName [PhysicalVolumePath...]

Common examples:

(1) Create a lv of the specified size and specify the name lv_2

lvcreate -L 2G -n lv_2 vg_1

(2) Create a lv that accounts for all volume groups and specify the name lv_3 (note that vg does not create lv)

lvcreate -l 100%VG -n lv_3 vg_1

（3）Create an lv with 80% of the size of free space and specify the name lv_4 (commonly used)

lvcreate -l 80%Free -n lv_4 vg_1