需求：服务器新添加一个挂载盘，为防止以后存储空间不够需要扩容时格式化磁盘，故使用LVM逻辑卷管理。
LVM简介：
LVM是 Logical Volume Manager（逻辑卷管理）的简写，它是Linux环境下对磁盘分区进行管理的一种机制，它由Heinz Mauelshagen在Linux 2.4内核上实现，目前最新版本为：稳定版1.0.5，开发版 1.1.0-rc2，以及LVM2开发版。Linux用户安装Linux操作系统时遇到的一个常见的难以决定的问题就是如何正确地评估各分区大小，以分配合适的硬盘空间。普通的磁盘分区管理方式在逻辑分区划分好之后就无法改变其大小，当一个逻辑分区存放不下某个文件时，这个文件因为受上层文件系统的限制，也不能跨越多个分区来存放，所以也不能同时放到别的磁盘上。而遇到出现某个分区空间耗尽时，解决的方法通常是使用符号链接，或者使用调整分区大小的工具，但这只是暂时解决办法，没有从根本上解决问题。随着Linux的逻辑卷管理功能的出现，这些问题都迎刃而解，用户在无需停机的情况下可以方便地调整各个分区大小。
LVM基本术语：
物理存储介质（The physical media）：这里指系统的存储设备：硬盘，如：/dev/hda1、/dev/sda等等，是存储系统最低层的存储单元。
物理卷（physical volume）：物理卷就是指硬盘分区或从逻辑上与磁盘分区具有同样功能的设备(如RAID)，是LVM的基本存储逻辑块，但和基本的物理存储介质（如分区、磁盘等）比较，却包含有与LVM相关的管理参数。
卷组（Volume Group）：LVM卷组类似于非LVM系统中的物理硬盘，其由物理卷组成。可以在卷组上创建一个或多个“LVM分区”（逻辑卷），LVM卷组由一个或多个物理卷组成。
逻辑卷（logical volume）：LVM的逻辑卷类似于非LVM系统中的硬盘分区，在逻辑卷之上可以建立文件系统(比如/home或者/usr等)。
PE（physical extent）：每一个物理卷被划分为称为PE(Physical Extents)的基本单元，具有唯一编号的PE是可以被LVM寻址的最小单元。PE的大小是可配置的，默认为4MB。
LE（logical extent）：逻辑卷也被划分为被称为LE(Logical Extents) 的可被寻址的基本单位。在同一个卷组中，LE的大小和PE是相同的，并且一一对应。
简单来说就是：
PV:是物理的磁盘分区
VG:LVM中的物理的磁盘分区，也就是PV，必须加入VG，可以将VG理解为一个仓库或者是几个大的硬盘。
LV：也就是从VG中划分的逻辑分区
1. 创建分区【8e为LVM分区格式】
[root@cqsjxw-nydsjpt01 ~]# fdisk /dev/vdc Welcome 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 table Building a new DOS disklabel with disk identifier 0x72334656. Command (m for help): p Disk /dev/vdc: 1073.7 GB, 1073741824000 bytes, 2097152000 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 Disk label type: dos Disk identifier: 0x72334656 Device Boot Start End Blocks Id System Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) e extended Select (default p): p Partition number (1-4, default 1): 1 First sector (2048-2097151999, default 2048): Using default value 2048 Last sector, +sectors or +size{K,M,G} (2048-2097151999, default 2097151999): Using default value 2097151999 Partition 1 of type Linux and of size 1000 GiB is set 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' Command (m for help): p Disk /dev/vdc: 1073.7 GB, 1073741824000 bytes, 2097152000 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 Disk label type: dos Disk identifier: 0x72334656 Device Boot Start End Blocks Id System /dev/vdc1 2048 2097151999 1048574976 8e Linux LVM Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
2. 创建PV
[root@cqsjxw-nydsjpt01 ~]# pvcreate /dev/vdc1 Physical volume "/dev/vdc1" successfully created. [root@cqsjxw-nydsjpt01 ~]# pvs PV VG Fmt Attr PSize PFree /dev/vda3 centos7 lvm2 a-- 39.80g 0 /dev/vdc1 lvm2 --- <1000.00g <1000.00g [root@cqsjxw-nydsjpt01 ~]# pvdisplay --- Physical volume --- PV Name /dev/vda3 VG Name centos7 PV Size 39.80 GiB / not usable 0 Allocatable yes (but full) PE Size 4.00 MiB Total PE 10189 Free PE 0 Allocated PE 10189 PV UUID VVXMV7-zVhi-NSVz-frrY-YKFg-BoJH-ir33p3 "/dev/vdc1" is a new physical volume of "<1000.00 GiB" --- NEW Physical volume --- PV Name /dev/vdc1 VG Name PV Size <1000.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID N6wQJb-K6Au-wto7-SR2O-jGrD-oZtQ-IcRlLI
3. 创建VG
[root@cqsjxw-nydsjpt01 ~]# vgcreate vgdata /dev/vdc1 Volume group "vgdata" successfully created [root@cqsjxw-nydsjpt01 ~]# vgs VG #PV #LV #SN Attr VSize VFree centos7 1 1 0 wz--n- 39.80g 0 vgdata 1 0 0 wz--n- <1000.00g <1000.00g [root@cqsjxw-nydsjpt01 ~]# vgdisplay --- Volume group --- VG Name vgdata System ID Format lvm2 Metadata Areas 1 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 1 Act PV 1 VG Size <1000.00 GiB PE Size 4.00 MiB Total PE 255999 Alloc PE / Size 0 / 0 Free PE / Size 255999 / <1000.00 GiB VG UUID MZjnmV-Gukd-XaH2-76jQ-wjik-LaWp-yqoHTQ --- Volume group --- VG Name centos7 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 2 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 1 Max PV 0 Cur PV 1 Act PV 1 VG Size 39.80 GiB PE Size 4.00 MiB Total PE 10189 Alloc PE / Size 10189 / 39.80 GiB Free PE / Size 0 / 0 VG UUID QTfxI7-AXVG-dGoO-zCQ8-wsFb-QlOe-HPSWPI
4. 物理卷存储划分给新的逻辑卷
[root@cqsjxw-nydsjpt01 ~]# lvcreate -L 999.90G -n lvdata01 vgdata Rounding up size to full physical extent 999.90 GiB Logical volume "lvdata01" created. [root@cqsjxw-nydsjpt01 ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root centos7 -wi-ao---- 39.80g lvdata01 vgdata -wi-a----- 999.90g [root@cqsjxw-nydsjpt01 ~]# lvdisplay --- Logical volume --- LV Path /dev/vgdata/lvdata01 LV Name lvdata01 VG Name vgdata LV UUID r83fGv-U3ju-Yn9k-yuXN-pEK6-ltTL-eSB2AO LV Write Access read/write LV Creation host, time cqsjxw-nydsjpt01, 2021-07-29 11:11:09 +0800 LV Status available # open 0 LV Size 999.90 GiB Current LE 255975 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:1 --- Logical volume --- LV Path /dev/centos7/root LV Name root VG Name centos7 LV UUID npjBgn-XPHe-dNS2-bJGd-kYp2-RayO-dWttAc LV Write Access read/write LV Creation host, time localhost, 2018-06-30 14:35:21 +0800 LV Status available # open 1 LV Size 39.80 GiB Current LE 10189 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0
5. 格式化逻辑卷文件系统
[root@cqsjxw-nydsjpt01 ~]# mkfs.ext4 /dev/vgdata/lvdata01 mke2fs 1.42.9 (28-Dec-2013) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 65536000 inodes, 262118400 blocks 13105920 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=2409627648 8000 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Allocating group tables: done Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done
6. 挂载逻辑卷
[root@cqsjxw-nydsjpt01 ~]# mount /dev/vgdata/lvdata01 /home [root@cqsjxw-nydsjpt01 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos7-root 40G 2.4G 38G 6% / devtmpfs 32G 0 32G 0% /dev tmpfs 32G 56K 32G 1% /dev/shm tmpfs 32G 282M 32G 1% /run tmpfs 32G 0 32G 0% /sys/fs/cgroup /dev/vda2 197M 120M 77M 61% /boot tmpfs 6.3G 0 6.3G 0% /run/user/0 /dev/mapper/vgdata-lvdata01 985G 77M 934G 1% /home [root@cqsjxw-nydsjpt01 ~]# cat /etc/fstab UUID=97f655c8-0ae8-489c-90be-594feaceaa27 /home ext4 defaults 0 0
7. 扩展逻辑卷【转载】
给逻辑卷增加空间并不会影响以前空间的使用，所以无需卸载文件系统，直接通过命令lvextend –L +500M /dev/vgdata/lvdata01或者lvextend –l 2.5G /dev/vgdata/lvdata01 给lvdata01增加500M空间（lvdata01目前是15G空间）设置完成之后，记得使用resize2fs命令来同步文件系统。
[root@DB02 ~]# lvextend -L +500M /dev/vgdata/lvdata01 Extending logical volume lvdata01 to 15.49 GiB Logical volume lvdata01 successfully resized [root@DB02 ~]# lvs LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert lvdata01 vgdata -wi-ao---- 15.49g [root@DB02 ~]# resize2fs /dev/vgdata/lvdata01 resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/vgdata/lvdata01 is mounted on /u01; on-line resizing required old desc_blocks = 1, new_desc_blocks = 1 Performing an on-line resize of /dev/vgdata/lvdata01 to 4060160 (4k) blocks. The filesystem on /dev/vgdata/lvdata01 is now 4060160 blocks long.
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