磁盘挂载命令cat 挂载磁盘的命令



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磁盘挂载命令cat 挂载磁盘的命令

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centos7.8配置lvm并挂载1 lvm是什么
LVM(Logic Volume Manager)即逻辑卷管理器 , 是linux系统用户对硬盘分区管理的一种机制 。创建初衷是为了解决硬盘设备在创建完分区后不易修改分区的问题 , LVM技术是在硬盘分区和文件系统之间加了一个逻辑层 , 他提供了一个抽象的卷组 , 可以把多个硬盘进行卷组合并 , 这样一来 , 用户就不用担心物理硬盘设备的底层架构布局 , 可以轻松实现对硬盘分区的动态调整 。简而言之就是动态添加、缩减空间 , 而不会影响原有数据 。
2 lvm原理及常用命令
PV(Physical Volume):物理卷
VG(Volume Group):卷组
LV(Logical Volume):逻辑卷
PE(Physical Extent):基本单元
【磁盘挂载命令cat 挂载磁盘的命令】物理卷处于LVM中的最底层 , 可以将其理解为物理硬盘、硬盘分区或者磁盘阵列 , 物理卷可以理解为一个磁盘分区 , 创建物理卷时指定磁盘分区 。卷组是建立在物理卷之上的 , 一个卷组可以包含多个物理卷 , 卷组创建之后也可以继续向其中添加物理卷 。逻辑卷是用卷组中空闲的资源建立的 , 而且逻辑卷在建立后可以动态地扩建或者缩小空间 。基本原理如图:(图片源自网络)
常用命令:
功能PV管理命令VG管理命令LV管理命令scan 扫描pvscanvgscanlvscancreate 创建pvcreatevgcreatelvcreatedisplay 显示pvdisplayvgdisplaylvdisplayremove 移除pvremovevgremovelvremoveextend 扩展vgextendlvextend(lvresize)reduce 减少vgreducelvreduce(lvresize)resize改变容量lvresizeattribute 改变属性 pvchangevgchangelvchange3 实操步骤
本次实操是在云平台上的磁盘上进行lvm的创建及空间分配 , 磁盘为/dev/vdb
1 格式化分区
依次输入:fdisk /dev/vdb
n:新建分区
p:主分区
默认回车
默认回车
t:调整分区类型
8e:调整为lvm类型分区
w:保存
[[email protected] ~]# fdisk /dev/vdbWelcome to fdisk (util-linux 2.23.2).Changes will remain in memory only, until you decide to write them.Be careful before using the write command.Device does not contain a recognized partition tableBuilding a new DOS disklabel with disk identifier 0xd3ff2d0b.Command (m for help): nPartition type:pprimary (0 primary, 0 extended, 4 free)eextendedSelect (default p): pPartition number (1-4, default 1):First sector (2048-419430399, default 2048):Using default value 2048Last sector, +sectors or +size{K,M,G} (2048-419430399, default 419430399):Using default value 419430399Partition 1 of type Linux and of size 200 GiB is setCommand (m for help): tSelected partition 1Hex code (type L to list all codes): 8eChanged type of partition 'Linux' to 'Linux LVM'Command (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.Syncing disks.2 创建pv
[[email protected] ~]# pvcreate /dev/vdb1Physical volume "/dev/vdb1" successfully created.#查看pv信息[[email protected] ~]# pvsPVVGFmtAttr PSizePFree/dev/vda2centos lvm2 a--<19.00g0/dev/vdb1lvm2 ---<200.00g <200.00g3 创建vg
[[email protected] ~]# vgcreate vg_test /dev/vdb1#第一个参数为vg名称 , 第二个参数为加入vg的pvVolume group "vg_test" successfully created#查看vg信息[[email protected] ~]# vgsVG#PV #LV #SN AttrVSizeVFreecentos120 wz--n-<19.00g0vg_test100 wz--n- <200.00g <200.00g4 创建lv , 并加入100%vg的剩余空间
[[email protected] ~]# lvcreate -n lv_test -l 100%FREE vg_test#创建名为lv_test的逻辑卷 , 并分配名为vg_test的卷组内所有分区空间的全部空闲空间Logical volume "lv_test" created.4 格式化
[[email protected] ~]# mkfs -t ext4 /dev/mapper/vg_test-lv_testmke2fs 1.42.9 (28-Dec-2013)Filesystem label=OS type: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks13107200 inodes, 52427776 blocks2621388 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=21999124481600 block groups32768 blocks per group, 32768 fragments per group8192 inodes per groupSuperblock backups stored on blocks:32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,4096000, 7962624, 11239424, 20480000, 23887872Allocating group tables: doneWriting inode tables: doneCreating journal (32768 blocks): doneWriting superblocks and filesystem accounting information: done#再次查看磁盘信息 , 就能看到这一个逻辑卷了[[email protected] ~]# fdisk -l#省略了部分输出Disk /dev/mapper/vg_test-lv_test: 214.7 GB, 214744170496 bytes, 419422208 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytes5 挂载磁盘
挂载磁盘不用磁盘名的方式 , 使用UUID挂载 , 更加可靠 。
[[email protected] ~]# blkid#查看创建的lv的UUID/dev/mapper/vg_test-lv_test: UUID="cdab99dd-fbf4-45f0-86ff-f55728d186cb" TYPE="ext4"[[email protected] ~]# vim /etc/fstab## /etc/fstab# Created by anaconda on Wed Aug 19 12:09:37 2020## 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 /xfsdefaults0 0UUID=4a6e8295-a8c1-479c-9890-cbab68fdfd68 /bootxfsdefaults0 0/dev/mapper/centos-swap swapswapdefaults0 0UUID=567b727c-af56-4d76-ae44-fb51b3c3944d /home/software ext4 defaults 0 0####/home/software 为要挂载的目录#挂载立即生效 , 不用重启[[email protected] ~]# mount -a地方-h6 查看挂载情况
[[email protected] ~]# df -hFilesystemSizeUsed Avail Use% Mounted on/dev/mapper/vg_test-lv_test197G61M187G1% /home/software