一、基本概念：
逻辑卷管理（Logical Volume Manager）：LVM将一个或多个硬盘的分区在逻辑上集合，相当于一个大硬盘来使用，
当硬盘的空间不够使用的时候，可以继续将其它的硬盘的分区加入其中，这样可以实现磁盘空间的动态管理。
物理存储介质（The Physical Media）：这里指系统的存储设备：硬盘（如/dev/sda），是存储系统最低层的存储单元。
物理卷（Physical Volume）：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。
卷组（Volume Group）：LVM卷组由一个或多个物理卷组成。可以在卷组上创建一个或多个逻辑卷。
逻辑卷（Logical Volume）：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 (如/home)，即为逻辑分区。
如下图所示PV、VG、LV三者关系：
二、常规操作及命令
1、实施LVM存储
# a.进入交互式界面后，创建新分区 fdisk /dev/sda # b.创建物理卷（pv） pvcreate /dev/sda4 ### 可使用pvs、pvdisplay查看 # c.创建卷组（vg） vgcreate vg4 /dev/sda4 ### 可使用vgs、vgdisplay查看 # d.创建逻辑卷（lv） lvcreate -n lv4 vg4 -L 1G ### 可使用lvs、lvdisplay查看 # e.建立文件系统（-t指定文件系统类型） mkfs -t xfs /dev/vg4/lv4 # f.挂载文件目录 mount /dev/vg4/lv4 /data //临时挂载 vi /etc/fstab //永久挂载（在配置文件追加） /dev/vg4/lv4 /data xfs defaults 0 0 # g.重新加载并查看效果 mount -a && df -Th
2、删除逻辑卷
# a.卸载挂载点 umount /data ### 若提示繁忙，可使用 fuser -m -k /data 结束掉 # b.删除逻辑卷 lvremove /dev/vg4/lv4 # c.删除卷组 vgremove vg4 # d.删除物理卷 pvremove /dev/sda4
3、扩展和缩减
# 假如vg容量不够，需要新建分区-创建物理卷-扩展卷组 fdisk /dev/sda pvcreate /dev/sda4 vgextend vg4 /dev/sda4 # 若想缩减卷组需要缩减卷组-缩减物理卷 vgreduce vg4 /dev/vg1 pvremove /dev/sda4 # 扩展逻辑卷后需根据文件系统类型进行扩展 lvextend /dev/vg4/lv1 -L 500M //将LV扩大至500M xfs_growfs /dev/vg4/lv4 //xfs文件系统扩展方法 resize2fs /dev/vg4/lv4 //ext4文件系统扩展方法
三、实战演示：
1、前期准备
a）以虚拟机作为演示，先查看磁盘信息（ fdisk -l ）和系统磁盘大小（df -h ），当前均为40G。
b）关机虚拟机，扩展磁盘大小到50G。
c）启动虚拟机，再次查看磁盘信息，增加到50G（系统磁盘还是40G，是因为磁盘没有做分区）。
2、创建和删除分区
a）创建一个普通分区（ fdisk /dev/sda ）
注意：不同操作系统的磁盘命名方式不同，比如Ubuntu是/dev/vda，请根据磁盘信息首行显示Disk值。
[root@k8s-master ~]# fdisk -l Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000a4e32 Device Boot Start End Blocks Id System /dev/sda1 * 2048 616447 307200 83 Linux /dev/sda2 616448 4812799 2098176 82 Linux swap / Solaris /dev/sda3 4812800 83886079 39536640 83 Linux [root@k8s-master ~]# [root@k8s-master ~]# fdisk /dev/sda 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. Command (m for help): m //查看帮助说明 Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition g create a new empty GPT partition table G create an IRIX (SGI) partition table l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partitions system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only) Command (m for help): n //创建分区 Partition type: p primary (3 primary, 0 extended, 1 free) //选择主分区（最多4个） e extended //扩展分区 Select (default e): p Selected partition 4 //选择分区号 First sector (83886080-104857599, default 83886080): //分区起始位置（空格则使用默认值） Using default value 83886080 Last sector, +sectors or +size{K,M,G} (83886080-104857599, default 104857599): Using default value 104857599 //分区结束位置（或指定大小+10G） Partition 4 of type Linux and of size 10 GiB is set Command (m for help): p //查看分区情况 Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000a4e32 Device Boot Start End Blocks Id System /dev/sda1 * 2048 616447 307200 83 Linux /dev/sda2 616448 4812799 2098176 82 Linux swap / Solaris /dev/sda3 4812800 83886079 39536640 83 Linux /dev/sda4 83886080 104857599 10485760 83 Linux Command (m for help): w //写入分区表 The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8) Syncing disks. [root@k8s-master ~]# partprobe //使分区表生效（无需重启）
b）创建一个LVM分区
[root@k8s-master ~]# fdisk /dev/sda 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. Command (m for help): n Partition type: p primary (3 primary, 0 extended, 1 free) e extended Select (default e): p Selected partition 4 First sector (83886080-104857599, default 83886080): Using default value 83886080 Last sector, +sectors or +size{K,M,G} (83886080-104857599, default 104857599): +5G Partition 4 of type Linux and of size 5 GiB is set //指定分区大小 Command (m for help): t //修改分区格式 Partition number (1-4, default 4): 4 //选择分区 Hex code (type L to list all codes): 8e //8e类型即为LVM Changed type of partition 'Linux' to 'Linux LVM' Command (m for help): p //查看当前分区 Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000a4e32 Device Boot Start End Blocks Id System /dev/sda1 * 2048 616447 307200 83 Linux /dev/sda2 616448 4812799 2098176 82 Linux swap / Solaris /dev/sda3 4812800 83886079 39536640 83 Linux /dev/sda4 83886080 94371839 5242880 8e Linux LVM
c）删除一个分区
[root@k8s-master ~]# fdisk /dev/sda 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. Command (m for help): d Partition number (1-4, default 4): 4 Partition 4 is deleted Command (m for help): q
3、挂载磁盘到指定目录
[root@Server]# mkfs.xfs -f /dev/vdb1 meta-data=/dev/vdb1 isize=512 agcount=4, agsize=32767936 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=0 = reflink=0 data = bsize=4096 blocks=131071744, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0, ftype=1 log =internal log bsize=4096 blocks=63999, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 [root@Server /]# mkdir /data [root@Server /]# mount /dev/vdb1 /data [root@Server /]# df -hT Filesystem Type Size Used Avail Use% Mounted on devtmpfs devtmpfs 16G 0 16G 0% /dev tmpfs tmpfs 16G 256K 16G 1% /dev/shm tmpfs tmpfs 16G 22M 16G 1% /run tmpfs tmpfs 16G 0 16G 0% /sys/fs/cgroup /dev/vda3 xfs 14G 7.9G 6.0G 58% / tmpfs tmpfs 16G 64K 16G 1% /tmp /dev/vda2 xfs 1014M 222M 793M 22% /boot /dev/vda1 vfat 200M 5.8M 195M 3% /boot/efi tmpfs tmpfs 3.2G 576K 3.2G 1% /run/user/0 /dev/sr1 iso9660 478K 478K 0 100% /run/media/root/config-2 /dev/vdb1 xfs 500G 543M 500G 1% /data [root@Server /]# echo "/dev/vdb1 /data xfs defaults 0 0" >> /etc/fstab [root@Server-6822768a-984b-4aa9-afb4-d6e34b24e4bc /]# cat /etc/fstab # # /etc/fstab # Created by anaconda on Tue Dec 1 10:40:10 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. # # After editing this file, run 'systemctl daemon-reload' to update systemd # units generated from this file. # UUID=f9d06f7f-0fe3-4dbf-8c30-2a8cd8f3ac3b / xfs defaults 0 0 UUID=c5f65c3b-114d-4c04-adf7-1e2e7351276e /boot xfs defaults 0 0 UUID=D071-A4FA /boot/efi vfat umask=0077,shortname=winnt 0 2 /dev/vdb1 /data xfs defaults 0 0 [root@Server /]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 16G 0 16G 0% /dev tmpfs 16G 256K 16G 1% /dev/shm tmpfs 16G 22M 16G 1% /run tmpfs 16G 0 16G 0% /sys/fs/cgroup /dev/vda3 14G 7.9G 6.0G 58% / tmpfs 16G 64K 16G 1% /tmp /dev/vda2 1014M 222M 793M 22% /boot /dev/vda1 200M 5.8M 195M 3% /boot/efi tmpfs 3.2G 576K 3.2G 1% /run/user/0 /dev/sr1 478K 478K 0 100% /run/media/root/config-2 /dev/vdb1 500G 543M 500G 1% /data
4、创建和删除逻辑卷
a）创建一个逻辑卷并挂载
注意：这里/dev/sda4 分区名请根据自己实际情况修改。
[root@k8s-master ~]# pvcreate /dev/sda4 Physical volume "/dev/sda4" successfully created. [root@k8s-master ~]# pvdisplay "/dev/sda4" is a new physical volume of "10.00 GiB" --- NEW Physical volume --- PV Name /dev/sda4 VG Name PV Size 10.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID bp2axz-XfE1-m1Ca-6BX4-G22d-uliq-1q88Ky [root@k8s-master ~]# vgcreate vg4 /dev/sda4 Volume group "vg4" successfully created [root@k8s-master ~]# vgdisplay --- Volume group --- VG Name vg4 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 0 Max PV 0 Cur PV 1 Act PV 1 VG Size <10.00 GiB PE Size 4.00 MiB Total PE 2559 Alloc PE / Size 256 / 1.00 GiB Free PE / Size 2303 / <9.00 GiB VG UUID 0zg2zi-EcJx-d26s-cTwN-XSqD-oF4H-pmo8UP [root@k8s-master ~]# lvcreate -n lv4 vg4 -L 1G Logical volume "lv4" created. [root@k8s-master ~]# lvdisplay --- Logical volume --- LV Path /dev/vg4/lv4 LV Name lv4 VG Name vg4 LV UUID FPWpmo-5cad-mRe1-LM3D-65ab-AcZW-kRxZpZ LV Write Access read/write LV Creation host, time k8s-master, 2021-06-11 02:56:36 -0700 LV Status available # open 0 LV Size 1.00 GiB Current LE 256 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0 [root@k8s-master ~]# mkfs -t xfs /dev/vg4/lv4 meta-data=/dev/vg4/lv4 isize=512 agcount=4, agsize=65536 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=0, sparse=0 data = bsize=4096 blocks=262144, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=1 log =internal log bsize=4096 blocks=2560, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 [root@k8s-master ~]# mkdir /data [root@k8s-master ~]# mount /dev/vg4/lv4 /data [root@k8s-master ~]# df -Th | grep data /dev/mapper/vg4-lv4 xfs 1014M 33M 982M 4% /data
b）删除一个逻辑卷
[root@k8s-master ~]# umount /data [root@k8s-master ~]# [root@k8s-master ~]# lvremove /dev/vg4/lv4 Do you really want to remove active logical volume vg4/lv4? [y/n]: y Logical volume "lv4" successfully removed [root@k8s-master ~]# [root@k8s-master ~]# lvremove /dev/vg4/lv4 Failed to find logical volume "vg4/lv4" [root@k8s-master ~]# [root@k8s-master ~]# vgremove vg4 Volume group "vg4" successfully removed [root@k8s-master ~]# [root@k8s-master ~]# pvremove /dev/sda4 Labels on physical volume "/dev/sda4" successfully wiped. [root@k8s-master ~]# [root@k8s-master ~]# df -hT | grep data [root@k8s-master ~]#
