Linux LVM磁盘管理

Posted 2021-02-04 Cyber Security

几个概念：

PV：物理卷，指LVM的基本逻辑卷，包含LVM的基本参数，如/dev/sdb1等。

VG：卷组，类似于非LVM的硬盘，由多个PV组成。

LV：逻辑卷，类似于非LVM硬盘中的分区。

PE：物理块，每个物理卷PV被划分成一个个PE大基本单元，具有唯一编号的PE是LVM的最小的寻址单元，PE的大小是可以配置的，默认为4M。

LE：逻辑块，逻辑卷LV被划分成可寻址的基本单元LE，在同一个卷组中，PE和LE是大小相同，并且一一对应的。

步骤：

Step1:在机器上插入120G的一块SAS硬盘，并且分区，初始化，配置分区的格式为LVM，使用fdisk分区指定参数为8e，如下图：

[[email protected] networking]# fdisk -l

Disk /dev/sdb: 128.8 GB, 128849018880 bytes, 251658240 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

[[email protected] networking]# fdisk /dev/sdb

Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): 8e

Changed type of partition ‘Linux‘ to ‘Linux LVM‘

Step2：创建PV，如下图：

[[email protected] networking]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
[[email protected] networking]#

Step3：创建VG，将创建的PV /dev/sdb1加入卷组，卷组的名称为RHEL

[[email protected] networking]# vgcreate RHEL /dev/sdb1
Volume group "RHEL" successfully created

Step4：创建LV，名称为Data，容量为60G，如下图：

[[email protected] networking]# lvcreate -L 60G -n Data RHEL
Logical volume "Data" created.

Step5：格式化LV，分区格式为xfs，如下图：

[[email protected] networking]# mkfs.xfs /dev/RHEL/Data
meta-data=/dev/RHEL/Data isize=256 agcount=4, agsize=3932160 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0
data = bsize=4096 blocks=15728640, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal log bsize=4096 blocks=7680, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[[email protected] networking]#

 Step6：创建挂载点/data，将分区挂载上去，如下图：

[[email protected] networking]# mkdir /data
[[email protected] networking]# mount /dev/RHEL/Data /data
[[email protected] networking]# df -hi
Filesystem Inodes IUsed IFree IUse% Mounted on
devtmpfs 484K 371 483K 1% /dev
tmpfs 491K 1 491K 1% /dev/shm
tmpfs 491K 462 490K 1% /run
tmpfs 491K 13 491K 1% /sys/fs/cgroup
/dev/mapper/centos-root 45M 69K 44M 1% /
/dev/sda1 500K 334 500K 1% /boot
/dev/mapper/centos-home 22M 8 22M 1% /home
tmpfs 491K 1 491K 1% /run/user/1000
/dev/mapper/RHEL-Data 60M 3 60M 1% /data
[[email protected] networking]#

 Step7：修改fstab开机挂载，如下图：

[[email protected] networking]# blkid /dev/RHEL/Data
/dev/RHEL/Data: UUID="9d9e1e69-9ad5-4d08-894c-50e111faf951" TYPE="xfs"

[[email protected] networking]# vi /etc/fstab 

# /etc/fstab
# Created by anaconda on Sun Jan 20 05:11:51 2019
#
# Accessible filesystems, by reference, are maintained under ‘/dev/disk‘
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=cd2fc291-2a9c-4479-b2c0-dddfbe129d6c /boot xfs defaults 0 0
/dev/mapper/centos-home /home xfs defaults 0 0
/dev/mapper/centos-swap swap swap defaults 0 0
UUID=9d9e1e69-9ad5-4d08-894c-50e111faf951 /data xfs defaults 0 0