# LVM扩容
# LVM基本拓扑
LVM构建在物理磁盘的分区之上，分别映射到各种文件系统的路径中
LVM（Logical Volume Manager（逻辑卷管理）的简写）文件系统由PV\VG\LV三层组合而来，其中
- PV与磁盘分区建立映射关系
- 多个PV构建成1个VG
- VG内部有多个LV,分别映射到多个路径
基于以上拓扑，LV的扩容分为几种情况
- 创建新分区
- 创建新的PV
- 从VG的剩余空间扩容LV
- VG剩余空间不足时，将新的PV添加到VG
# 扩容LV
当VG空间足够时，直接扩容LV即可。
首先查看lv的情况:lvdisplay
$ lvdisplay
--- Logical volume ---
LV Path /dev/abc/swap
LV Name swap
VG Name abc
LV UUID dyZb7i-D1Fm-m9t6-7xW6-VTJb-StU1-e9Vptn
LV Write Access read/write
LV Creation host, time abc, 2020-07-20 00:48:18 +0800
LV Status available
# open 0
LV Size 7.00 GiB
Current LE 1792
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Path /dev/abc/root
LV Name root
VG Name abc
LV UUID MvicDp-Brid-U9RX-9Uaz-KccO-3VDX-GiuzRH
LV Write Access read/write
LV Creation host, time abc, 2020-07-20 00:48:18 +0800
LV Status available
# open 1
LV Size 255.75 GiB
Current LE 65472
Segments 3
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
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扩容LV:lvextend
使用下面的命令将现有的逻辑卷增加 10GB：
# lvextend -L +10G /dev/mapper/vg01-lv002
Rounding size to boundary between physical extents: 5.90 GiB
Size of logical volume vg01/lv002 changed from 5.00 GiB (1280 extents) to 15.00 GiB (3840 extents).
Logical volume var successfully resized
使用 PE 大小来扩展逻辑卷：
# lvextend -l +2560 /dev/mapper/vg01-lv002
要使用百分比（%）扩展逻辑卷，使用以下命令：
# lvextend -l +40%FREE /dev/mapper/vg01-lv002
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现在，逻辑卷已经扩展，你需要调整文件系统的大小以扩展逻辑卷内的空间：
对于基于 ext3 和 ext4 的文件系统，运行以下命令：
# resize2fs /dev/mapper/vg01-lv002
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对于 xfs 文件系统，使用以下命令：
# xfs_growfs /dev/mapper/vg01-lv002
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# 创建新分区
Linux中创建新分区使用fdisk命令，参考CSDN博客 (opens new window)，基本用法
查看当前磁盘情况
sudo fdisk -l1## 输出类似 Disk /dev/sda: 953.87 GiB, 1024209543168 bytes, 2000409264 sectors Disk model: WD Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 5DD86641-3E91-42BB-BB40-46DD08A44BD0 Device Start End Sectors Size Type /dev/sda1 34 32767 32734 16M Linux filesystem /dev/sda2 32768 921399295 921366528 439.3G Linux filesystem /dev/sda3 1794013184 1794990079 976896 477M EFI System /dev/sda4 1794990080 2000409230 205419151 98G Linux filesystem /dev/sda5 921399296 1794013183 872613888 416.1G Linux filesystem1
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15在指定磁盘执行fdisk命令
sudo fdisk /dev/[你的磁盘比如sda]1Welcome to fdisk (util-linux 2.31.1). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help):1
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m，查看fdisk相关命令Command (m for help): m Help: Generic d delete a partition F list free unpartitioned space l list known partition types n add a new partition p print the partition table t change a partition type v verify the partition table i print information about a partition Misc m print this menu x extra functionality (experts only) Script I load disk layout from sfdisk script file O dump disk layout to sfdisk script file Save & Exit w write table to disk and exit q quit without saving changes Create a new label g create a new empty GPT partition table G create a new empty SGI (IRIX) partition table o create a new empty DOS partition table s create a new empty Sun partition table1
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p，打印当前磁盘的分区表Command (m for help): m Device Start End Sectors Size Type /dev/sda1 34 32767 32734 16M Linux filesystem /dev/sda2 32768 921399295 921366528 439.3G Linux filesystem /dev/sda3 1794013184 1794990079 976896 477M EFI System /dev/sda4 1794990080 2000409230 205419151 98G Linux filesystem /dev/sda5 921399296 1794013183 872613888 416.1G Linux filesystem1
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F(大写)，打印当前可分配空间Command (m for help): F Unpartitioned space /dev/sda: 1007.5 KiB, 1031680 bytes, 2015 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes1
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n,创建新分区Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) 注：0个主分区，4个空闲分区 e extended 注：扩展分区 Select (default p): e 注：添加主分区，默认主分区； Partition number (1-4, default 1): 3 注：添加分区3，非特殊情况建议默认 First sector (2048-39843839, default 2048): 注：直接回车，分区的开始位置。非特殊情况建议默认 Using default value 2048 Last sector, +sectors or +size{K,M,G} (2099200-209715199, default 209715199): +2G 注：指定分区大小，用+2G来指定大小为2G，如果全部使用则直接回车1
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10目前新分区还未生效，在生效之前执行
p打印命令最终确认执行
w命令写入，新分区创建完成Command (m for help): w The partition table has been altered!1
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# 创建新PV
将刚才创建的新分区创建为新PV
pvcreate /dev/sda3[这里是具体的分区所以有数字]
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完成后查看新创建的pv：pvdisplay
$ pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name ubuntu-vg
PV Size <63.00 GiB / not usable 1.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 16127
Free PE 0
Allocated PE 16127
PV UUID w7V6F0-EWbw-aTyZ-ABCD-yfjk-4Vgj-XqQnhe
--- NEW Physical volume ---
PV Name /dev/sda3
VG Name
PV Size 10.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 69d9dd18-36be-ABCD-9ebb-78f05fe3217f
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# 新创建的PV加入VG
首先查看当前的VG组:vgdisplay
$ vgdisplay
--- Volume group ---
VG Name vg01
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 14.99 GiB
PE Size 4.00 MiB
Total PE 3840
Alloc PE / Size 1280 / 4.99
Free PE / Size 2560 / 9.99 GiB
VG UUID d17e3c31-e2c9-4f11-809c-94a549bc43b7
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执行扩容动作::vgextend
vgextend vg01 /dev/sda3[pv]
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# 验证效果
使用 df 命令查看文件系统大小：
# df -h /lvmtest1
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg01-lv002 15360M 34M 15326M 4% /lvmtest1
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