一、前言
LVM，逻辑卷管理工具，它的作用是提供一种灵活的磁盘管理办法。通常我们的某个分区用完了，想要扩容，很麻烦。但是用lvm就可以很方便的扩容，收缩。
看它的原理图：
它的原理大致是：首先将磁盘做成物理卷，然后物理卷再组成卷组，卷组下面再划分逻辑卷。
二、实现一个lvm
步骤：
2.1 做物理卷。
首先看看我们的磁盘/dev/sdb的分区情况：
[[email protected] ~]# fdisk -l /dev/sdb 磁盘 /dev/sdb：4294 MB, 4294967296 字节，8388608 个扇区 Units = 扇区 of 1 * 512 = 512 bytes 扇区大小(逻辑/物理)：512 字节 / 512 字节 I/O 大小(最小/最佳)：512 字节 / 512 字节 磁盘标签类型：dos 磁盘标识符：0x2f45f776 设备 Boot Start End Blocks Id System /dev/sdb1 2048 2099199 1048576 83 Linux /dev/sdb2 6293504 7931903 819200 83 Linux /dev/sdb3 2099200 6293503 2097152 5 Extended /dev/sdb5 2101248 4198399 1048576 83 Linux /dev/sdb6 4200448 5838847 819200 83 Linux
接下来，我们把sdb1，sdb2，sdb5的分区id修改为8e：
[[email protected] ~]# fdisk /dev/sdb 欢迎使用 fdisk (util-linux 2.23.2)。 更改将停留在内存中，直到您决定将更改写入磁盘。 使用写入命令前请三思。 命令(输入 m 获取帮助)：t 分区号 (1-3,5,6，默认 6)：1 Hex 代码(输入 L 列出所有代码)：8e 已将分区“Linux”的类型更改为“Linux LVM” 命令(输入 m 获取帮助)：t 分区号 (1-3,5,6，默认 6)：2 Hex 代码(输入 L 列出所有代码)：8e 已将分区“Linux”的类型更改为“Linux LVM” 命令(输入 m 获取帮助)：t 分区号 (1-3,5,6，默认 6)：5 Hex 代码(输入 L 列出所有代码)：8e 已将分区“Linux”的类型更改为“Linux LVM” 命令(输入 m 获取帮助)：p 磁盘 /dev/sdb：4294 MB, 4294967296 字节，8388608 个扇区 Units = 扇区 of 1 * 512 = 512 bytes 扇区大小(逻辑/物理)：512 字节 / 512 字节 I/O 大小(最小/最佳)：512 字节 / 512 字节 磁盘标签类型：dos 磁盘标识符：0x2f45f776 设备 Boot Start End Blocks Id System /dev/sdb1 2048 2099199 1048576 8e Linux LVM /dev/sdb2 6293504 7931903 819200 8e Linux LVM /dev/sdb3 2099200 6293503 2097152 5 Extended /dev/sdb5 2101248 4198399 1048576 8e Linux LVM /dev/sdb6 4200448 5838847 819200 83 Linux Partition table entries are not in disk order
如果是新创建的分区，找不到的话，使用partprobe命令刷新一下。
运行pvcreate命令，创建物理卷(physical volum)
[[email protected] ~]# pvs -bash: pvs: 未找到命令 [[email protected] ~]# pvdisplay -bash: pvdisplay: 未找到命令
发现这些命令都没有的话，那么就需要安装lvm2：
[[email protected] ~]# yum install lvm2 已加载插件：fastestmirror base | 3.6 kB 00:00:00 extras | 3.4 kB 00:00:00 updates | 3.4 kB 00:00:00 (1/2): extras/7/x86_64/primary_db | 129 kB 00:00:00 (2/2): updates/7/x86_64/primary_db
安装好之后，就可以使用pvcreate命令了：
[[email protected] ~]# pvcreate /dev/sdb1 WARNING: ext2 signature detected on /dev/sdb1 at offset 1080. Wipe it? [y/n]: y Wiping ext2 signature on /dev/sdb1. Physical volume "/dev/sdb1" successfully created. [[email protected] ~]# pvcreate /dev/sdb2 Physical volume "/dev/sdb2" successfully created. [[email protected] ~]# pvcreate /dev/sdb5 Physical volume "/dev/sdb5" successfully created.
运行pvs或者pvdisplay命令能查看当前的物理卷：
[[email protected] ~]# pvs PV VG Fmt Attr PSize PFree /dev/sdb1 lvm2 --- 1.00g 1.00g /dev/sdb2 lvm2 --- 800.00m 800.00m /dev/sdb5 lvm2 --- 1.00g 1.00g [[email protected] ~]# pvdisplay "/dev/sdb2" is a new physical volume of "800.00 MiB" --- NEW Physical volume --- PV Name /dev/sdb2 VG Name PV Size 800.00 MiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID FS2sy9-BTxn-XzCz-6ZBH-fL04-r1mB-p2EH91 "/dev/sdb5" is a new physical volume of "1.00 GiB" --- NEW Physical volume --- PV Name /dev/sdb5 VG Name PV Size 1.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID 6iKVQF-W01Z-1aMF-m1af-jmhX-Ff7c-r5QHcD "/dev/sdb1" is a new physical volume of "1.00 GiB" --- NEW Physical volume --- PV Name /dev/sdb1 VG Name PV Size 1.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID lttH1f-3tce-mEpF-2ULq-nqmL-15SI-2ImIxc
2.2 创建卷组
[[email protected] ~]# vgcreate vg1 /dev/sdb sdb sdb1 sdb2 sdb3 sdb5 sdb6 [[email protected] ~]# vgcreate vg1 /dev/sdb1 /dev/sdb2 Volume group "vg1" successfully created [[email protected] ~]# vgcreate vg2 /dev/sdb5 Volume group "vg2" successfully created [[email protected] ~]# vgs VG #PV #LV #SN Attr VSize VFree vg1 2 0 0 wz--n- 1.77g 1.77g vg2 1 0 0 wz--n- 1020.00m 1020.00m [[email protected] ~]# vgdisplay --- Volume group --- VG Name vg2 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 1020.00 MiB PE Size 4.00 MiB Total PE 255 Alloc PE / Size 0 / 0 Free PE / Size 255 / 1020.00 MiB VG UUID aDXygA-rltJ-JWCQ-Nbvb-JML9-W3Hf-cVjG63 --- Volume group --- VG Name vg1 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 1.77 GiB PE Size 4.00 MiB Total PE 454 Alloc PE / Size 0 / 0 Free PE / Size 454 / 1.77 GiB VG UUID qxqwsD-oNGT-8ltJ-1Itj-IZfO-0rui-Yxvhh7
使用vgs或者vgdisplay可以看到卷组。
2.3 创建逻辑卷
现在我们创建了两个卷组，一个是vg1的1.7G，一个是vg2的1G。接下来我们创建逻辑卷：
[[email protected] ~]# lvcreate -L 200M -n lv1 vg1 Logical volume "lv1" created.
创建的逻辑需要被格式化之后才可以使用：
[[email protected] ~]# mke2fs -t ext4 /dev/vg1/lv1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=1024 (log=0)
分块大小=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
51200 inodes, 204800 blocks
10240 blocks (5.00%) reserved for the super user
第一个数据块=1
Maximum filesystem blocks=33816576
25 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (4096 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
我们采用的ext4的文件系统格式化的，使用xfs的文件系统格式化也是可以的。
我们把格式化完成之后/dev/vg1/lv1挂载到/mnt目录下
[[email protected] ~]# mkdir /mnt/vg1 [[email protected] ~]# mount /dev/vg1/lv1 /mnt/vg1/ [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 18G 1.4G 17G 8% / devtmpfs 479M 0 479M 0% /dev tmpfs 489M 0 489M 0% /dev/shm tmpfs 489M 6.8M 482M 2% /run tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda1 197M 109M 88M 56% /boot tmpfs 98M 0 98M 0% /run/user/0 /dev/mapper/vg1-lv1 190M 1.6M 175M 1% /mnt/vg1 [[email protected] ~]# cat /etc/passwd >> /mnt/vg1/passwd [[email protected] ~]# cat !$ cat /mnt/vg1/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-bus-proxy:x:999:997:systemd Bus Proxy:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:998:996:User for polkitd:/:/sbin/nologin tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin ruanwenwu:x:1000:1000::/home/ruanwenwu:/bin/bash
到这里，我们的逻辑卷创建也结束了。
如果，我们要删除一个物理卷怎么操作呢？
[[email protected] ~]# pvremove /dev/sdb2 PV /dev/sdb2 is used by VG vg1 so please use vgreduce first. (If you are certain you need pvremove, then confirm by using --force twice.) /dev/sdb2: physical volume label not removed. [[email protected] ~]# man vdreduce 没有 vdreduce 的手册页条目 [[email protected] ~]# man vgreduce [[email protected] ~]# man vgreduce [[email protected] ~]# vgreduce vg1 /dev/sdb2 Removed "/dev/sdb2" from volume group "vg1" [[email protected] ~]# vgs VG #PV #LV #SN Attr VSize VFree vg1 1 1 0 wz--n- 1020.00m 820.00m vg2 1 0 0 wz--n- 1020.00m 1020.00m [[email protected] ~]# pvs PV VG Fmt Attr PSize PFree /dev/sdb1 vg1 lvm2 a-- 1020.00m 820.00m /dev/sdb2 lvm2 --- 800.00m 800.00m /dev/sdb5 vg2 lvm2 a-- 1020.00m 1020.00m [[email protected] ~]# pvremove /dev/sdb2 Labels on physical volume "/dev/sdb2" successfully wiped. [[email protected] ~]# pvs PV VG Fmt Attr PSize PFree /dev/sdb1 vg1 lvm2 a-- 1020.00m 820.00m /dev/sdb5 vg2 lvm2 a-- 1020.00m 1020.00m
代码里碰到一个问题。如果一个物理卷已经被加入一个卷组里，需要使用vgreduce命令把这个物理卷从卷组里删除，然后再运行pvremove命令。
除了删除物理卷之外，逻辑卷也是可以删除的，使用命令lvremove /dev/vg1/lv1。
[[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv1 vg1 -wi-ao---- 200.00m [[email protected] ~]# lvremove /dev/vg1/lv1 Logical volume vg1/lv1 contains a filesystem in use. [[email protected] ~]# pwd /root [[email protected] ~]# rm -rf /dev/vg1/lv1/* [[email protected] ~]# !lv lvremove /dev/vg1/lv1 Logical volume vg1/lv1 contains a filesystem in use. [[email protected] ~]# umount /dev/vg1/lv1 [[email protected] ~]# !lv lvremove /dev/vg1/lv1 Do you really want to remove active logical volume vg1/lv1? [y/n]: y Logical volume "lv1" successfully removed [[email protected] ~]# lvs [[email protected] ~]# pvs PV VG Fmt Attr PSize PFree /dev/sdb1 vg1 lvm2 a-- 1020.00m 1020.00m /dev/sdb5 vg2 lvm2 a-- 1020.00m 1020.00m
现在我们再次将逻辑卷加回来：
[[email protected] ~]# history|grep lvcreate
235 lvcreate -L 200M -n lv1 vg1
273 history|lvcreate
274 history|grep lvcreate
[[email protected] ~]# lvcreate -L 200M -n lv1 vg1
WARNING: ext4 signature detected on /dev/vg1/lv1 at offset 1080. Wipe it? [y/n]: y
Wiping ext4 signature on /dev/vg1/lv1.
Logical volume "lv1" created.
[[email protected] ~]# mke2fs -t ext4 /dev/vg1/lv1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=1024 (log=0)
分块大小=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
51200 inodes, 204800 blocks
10240 blocks (5.00%) reserved for the super user
第一个数据块=1
Maximum filesystem blocks=33816576
25 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (4096 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
[[email protected] ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv1 vg1 -wi-a----- 200.00m
[[email protected] ~]# mount /dev/vg1/lv1 /mnt/vg1/
[[email protected] ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3 18G 1.4G 17G 8% /
devtmpfs 479M 0 479M 0% /dev
tmpfs 489M 0 489M 0% /dev/shm
tmpfs 489M 6.8M 482M 2% /run
tmpfs 489M 0 489M 0% /sys/fs/cgroup
/dev/sda1 197M 109M 88M 56% /boot
tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/vg1-lv1 190M 1.6M 175M 1% /mnt/vg1
到这里，我们的LVM基本上做完了。我们来梳理一下我们现有有了那些东西：
物理卷：
[[email protected] ~]# pvs PV VG Fmt Attr PSize PFree /dev/sdb1 vg1 lvm2 a-- 1020.00m 820.00m /dev/sdb5 vg2 lvm2 a-- 1020.00m 1020.00m
卷组：
[[email protected] ~]# vgs VG #PV #LV #SN Attr VSize VFree vg1 1 1 0 wz--n- 1020.00m 820.00m vg2 1 0 0 wz--n- 1020.00m 1020.00m
物理卷：
[[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv1 vg1 -wi-ao---- 200.00m
三、接下来讲如何扩容。
（先以ext4文件系统举例）
[[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv1 vg1 -wi-ao---- 200.00m [[email protected] ~]# lvresize -L 300M /dev/vg1/lv1 Size of logical volume vg1/lv1 changed from 200.00 MiB (50 extents) to 300.00 MiB (75 extents). Logical volume vg1/lv1 successfully resized. [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 18G 1.4G 17G 8% / devtmpfs 479M 0 479M 0% /dev tmpfs 489M 0 489M 0% /dev/shm tmpfs 489M 6.8M 482M 2% /run tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda1 197M 109M 88M 56% /boot tmpfs 98M 0 98M 0% /run/user/0 /dev/mapper/vg1-lv1 190M 1.6M 175M 1% /mnt/vg1 [[email protected] ~]# e2fsck -f /dev/vg1/lv1 e2fsck 1.42.9 (28-Dec-2013) /dev/vg1/lv1 is mounted. e2fsck: 无法继续, 中止.
这说明ext4文件系统扩容的话需要先umount：
[[email protected] ~]# lvresize -L 300M /dev/vg1/lv1 Size of logical volume vg1/lv1 changed from 200.00 MiB (50 extents) to 300.00 MiB (75 extents). Logical volume vg1/lv1 successfully resized. [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 18G 1.4G 17G 8% / devtmpfs 479M 0 479M 0% /dev tmpfs 489M 0 489M 0% /dev/shm tmpfs 489M 6.8M 482M 2% /run tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda1 197M 109M 88M 56% /boot tmpfs 98M 0 98M 0% /run/user/0 /dev/mapper/vg1-lv1 190M 1.6M 175M 1% /mnt/vg1 [[email protected] ~]# e2fsck -f /dev/vg1/lv1 e2fsck 1.42.9 (28-Dec-2013) /dev/vg1/lv1 is mounted. e2fsck: 无法继续, 中止. [[email protected] ~]# umount /dev/vg1/lv1 [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 18G 1.4G 17G 8% / devtmpfs 479M 0 479M 0% /dev tmpfs 489M 0 489M 0% /dev/shm tmpfs 489M 6.8M 482M 2% /run tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda1 197M 109M 88M 56% /boot tmpfs 98M 0 98M 0% /run/user/0 [[email protected] ~]# lvresize -L 300M /dev/vg1/lv1 New size (75 extents) matches existing size (75 extents). [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 18G 1.4G 17G 8% / devtmpfs 479M 0 479M 0% /dev tmpfs 489M 0 489M 0% /dev/shm tmpfs 489M 6.8M 482M 2% /run tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda1 197M 109M 88M 56% /boot tmpfs 98M 0 98M 0% /run/user/0 [[email protected] ~]# mount /dev/vg1/lv1 mount: 在 /etc/fstab 中找不到 /dev/vg1/lv1 [[email protected] ~]# e2fsck /dev/vg1/lv1 e2fsck 1.42.9 (28-Dec-2013) /dev/vg1/lv1: clean, 11/51200 files, 12115/204800 blocks [[email protected] ~]# resize2fs /dev/vg1/lv1 resize2fs 1.42.9 (28-Dec-2013) 请先运行 ‘e2fsck -f /dev/vg1/lv1‘. [[email protected] ~]# resize2fs -f /dev/vg1/lv1 resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/vg1/lv1 to 307200 (1k) blocks. The filesystem on /dev/vg1/lv1 is now 307200 blocks long. [[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv1 vg1 -wi-a----- 300.00m [[email protected] ~]# mount /dev/vg1/lv1 mount: 在 /etc/fstab 中找不到 /dev/vg1/lv1 [[email protected] ~]# e2fsck -f /dev/vg1/lv1 e2fsck 1.42.9 (28-Dec-2013) 第一步: 检查inode,块,和大小 第二步: 检查目录结构 第3步: 检查目录连接性 Pass 4: Checking reference counts 第5步: 检查簇概要信息 /dev/vg1/lv1: 11/77824 files (0.0% non-contiguous), 15987/307200 blocks [[email protected] ~]# lvresize /dev/vg1/lv1 No command with matching syntax recognised. Run ‘lvresize --help‘ for more information. [[email protected] ~]# resize2fs /dev/vg1/lv1 resize2fs 1.42.9 (28-Dec-2013) The filesystem is already 307200 blocks long. Nothing to do! [[email protected] ~]# ls -ld /dev/vg1/lv1 lrwxrwxrwx. 1 root root 7 11月 4 12:42 /dev/vg1/lv1 -> ../dm-0 [[email protected] ~]# mount /dev/vg1/lv1 /mnt/vg1/ [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 18G 1.4G 17G 8% / devtmpfs 479M 0 479M 0% /dev tmpfs 489M 0 489M 0% /dev/shm tmpfs 489M 6.8M 482M 2% /run tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda1 197M 109M 88M 56% /boot tmpfs 98M 0 98M 0% /run/user/0 /dev/mapper/vg1-lv1 287M 2.1M 266M 1% /mnt/vg1
总结一下步骤：
lvresize -L 300M /dev/vg1/lv1 重新设置卷大小 e2fsck -f /dev/vg1/lv1 检查磁盘错误 (ext4执行) resize2fs /dev/vg1/lv1 更新逻辑卷信息(ext4执行) xfs_growfs /dev/vg1/lv1 xfs文件系统需要执行
到这里扩容就成功了。
四、缩容
步骤：
缩减逻辑卷（xfs不支持） 先umount e2fsck -f /dev/vg1/lv1 检查磁盘错误（ext） resize2fs /dev/vg1/lv1 100M 更新逻辑卷信息（ext） lvresize -L 100M /dev/vg1/lv1 重新设置卷大小
实验：
[[email protected] ~]# umount /dev/vg1/lv1 [[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv1 vg1 -wi-a----- 100.00m [[email protected] ~]# e2fsck -f /dev/vg1/lv1 e2fsck 1.42.9 (28-Dec-2013) 第一步: 检查inode,块,和大小 第二步: 检查目录结构 第3步: 检查目录连接性 Pass 4: Checking reference counts 第5步: 检查簇概要信息 /dev/vg1/lv1: 11/25688 files (9.1% non-contiguous), 8896/102400 blocks [[email protected] ~]# resize2fs /dev/vg1/lv1 100M resize2fs 1.42.9 (28-Dec-2013) The filesystem is already 102400 blocks long. Nothing to do! [[email protected] ~]# resize2fs /dev/vg1/lv1 50M resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/vg1/lv1 to 51200 (1k) blocks. The filesystem on /dev/vg1/lv1 is now 51200 blocks long. [[email protected] ~]# lvresize -L 50M /dev/vg1/lv1 Rounding size to boundary between physical extents: 52.00 MiB. WARNING: Reducing active logical volume to 52.00 MiB. THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce vg1/lv1? [y/n]: y Size of logical volume vg1/lv1 changed from 100.00 MiB (25 extents) to 52.00 MiB (13 extents). Logical volume vg1/lv1 successfully resized. [[email protected] ~]# mount /dev/vg1/lv1 /mnt/vg1/ [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 18G 1.4G 17G 8% / devtmpfs 479M 0 479M 0% /dev tmpfs 489M 0 489M 0% /dev/shm tmpfs 489M 6.8M 482M 2% /run tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda1 197M 109M 88M 56% /boot tmpfs 98M 0 98M 0% /run/user/0 /dev/mapper/vg1-lv1 45M 1.1M 40M 3% /mnt/vg1
五、扩展卷组
步骤：
fdisk /dev/sdb 新增/dev/sdb5(逻辑分区8e) 2G pvcreate /dev/sdb5 vgextend vg1 /dev/sdb5 lvresize -L 100M /dev/vg1/lv1 重新设置卷大小
先创建一个分区，创建物理分区，将物理分区添加到卷组，然后重新分配卷大小。
[[email protected] ~]# fdisk /dev/sdb 欢迎使用 fdisk (util-linux 2.23.2)。 更改将停留在内存中，直到您决定将更改写入磁盘。 使用写入命令前请三思。 命令(输入 m 获取帮助)：t 分区号 (1-3,5,6，默认 6)：6 Hex 代码(输入 L 列出所有代码)：8e 已将分区“Linux”的类型更改为“Linux LVM” 命令(输入 m 获取帮助)：q [[email protected] ~]# pvcreate /dev/sdb6 WARNING: ext4 signature detected on /dev/sdb6 at offset 1080. Wipe it? [y/n]: y Wiping ext4 signature on /dev/sdb6. Physical volume "/dev/sdb6" successfully created. [[email protected] ~]# vgex vgexport vgextend [[email protected] ~]# vgex vgexport vgextend [[email protected] ~]# vgextend vg1 /dev/sdb6 Volume group "vg1" successfully extended [[email protected] ~]# vgdisplay -v --- Volume group --- VG Name vg2 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 1020.00 MiB PE Size 4.00 MiB Total PE 255 Alloc PE / Size 0 / 0 Free PE / Size 255 / 1020.00 MiB VG UUID aDXygA-rltJ-JWCQ-Nbvb-JML9-W3Hf-cVjG63 --- Physical volumes --- PV Name /dev/sdb5 PV UUID 6iKVQF-W01Z-1aMF-m1af-jmhX-Ff7c-r5QHcD PV Status allocatable Total PE / Free PE 255 / 255 --- Volume group --- VG Name vg1 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 9 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 1 Max PV 0 Cur PV 2 Act PV 2 VG Size 1.77 GiB PE Size 4.00 MiB Total PE 454 Alloc PE / Size 13 / 52.00 MiB Free PE / Size 441 / 1.72 GiB VG UUID qxqwsD-oNGT-8ltJ-1Itj-IZfO-0rui-Yxvhh7 --- Logical volume --- LV Path /dev/vg1/lv1 LV Name lv1 VG Name vg1 LV UUID x6wfyb-ZMDC-eGmK-8TRH-cVX5-JZB2-u0ZYID LV Write Access read/write LV Creation host, time ruanwenwu02, 2017-11-04 11:52:34 +0800 LV Status available # open 1 LV Size 52.00 MiB Current LE 13 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0 --- Physical volumes --- PV Name /dev/sdb1 PV UUID lttH1f-3tce-mEpF-2ULq-nqmL-15SI-2ImIxc PV Status allocatable Total PE / Free PE 255 / 242 PV Name /dev/sdb6 PV UUID QsRgrb-3vmW-Jte1-o5Qv-JvgZ-oNnO-MJkOoG PV Status allocatable Total PE / Free PE 199 / 199
六、命令整理：
6.1 fdisk diskname -> t ->8e
修改磁盘分区为lvm类型。
6.2 pvcreate partionname
创建物理分区
6.4 pvremove
删除物理分区
6.3 vgcreate vg1 /dev/sdb1 /dev/sdb2
创建卷组
6.4 vgremove
移除卷组
6.5 lvcreate -L 200M -n lv1 vg1
创建逻辑卷
6.6 lvresize -L 300M /dev/vg1/lv1
扩容逻辑卷大小
6.7 扩容之后的操作
e2fsck -f /dev/vg1/lv1 检查磁盘错误 (ext4执行) resize2fs /dev/vg1/lv1 更新逻辑卷信息(ext4执行) xfs_growfs /dev/vg1/lv1 xfs文件系统需要执行
6.8 缩容操作
先umount e2fsck -f /dev/vg1/lv1 检查磁盘错误（ext） resize2fs /dev/vg1/lv1 100M 更新逻辑卷信息（ext） lvresize -L 100M /dev/vg1/lv1 重新设置卷大小
6.9 列出卷组的详细信息
[[email protected] ~]# vgdisplay -v --- Volume group --- VG Name vg2 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 1020.00 MiB PE Size 4.00 MiB Total PE 255 Alloc PE / Size 0 / 0 Free PE / Size 255 / 1020.00 MiB VG UUID aDXygA-rltJ-JWCQ-Nbvb-JML9-W3Hf-cVjG63 --- Physical volumes --- PV Name /dev/sdb5 PV UUID 6iKVQF-W01Z-1aMF-m1af-jmhX-Ff7c-r5QHcD PV Status allocatable Total PE / Free PE 255 / 255 --- Volume group --- VG Name vg1 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 9 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 1 Max PV 0 Cur PV 2 Act PV 2 VG Size 1.77 GiB PE Size 4.00 MiB Total PE 454 Alloc PE / Size 13 / 52.00 MiB Free PE / Size 441 / 1.72 GiB VG UUID qxqwsD-oNGT-8ltJ-1Itj-IZfO-0rui-Yxvhh7 --- Logical volume --- LV Path /dev/vg1/lv1 LV Name lv1 VG Name vg1 LV UUID x6wfyb-ZMDC-eGmK-8TRH-cVX5-JZB2-u0ZYID LV Write Access read/write LV Creation host, time ruanwenwu02, 2017-11-04 11:52:34 +0800 LV Status available # open 1 LV Size 52.00 MiB Current LE 13 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0 --- Physical volumes --- PV Name /dev/sdb1 PV UUID lttH1f-3tce-mEpF-2ULq-nqmL-15SI-2ImIxc PV Status allocatable Total PE / Free PE 255 / 242 PV Name /dev/sdb6 PV UUID QsRgrb-3vmW-Jte1-o5Qv-JvgZ-oNnO-MJkOoG PV Status allocatable Total PE / Free PE 199 / 199
七、总结
LVM的命令还是比较多的，有机会多看看多练练吧。
时间： 2024-11-09 00:05:35