Linux之lvm
lvm的用法
使用 lvm 可以方便的扩容或者缩容磁盘空间
如下例:
首先需要安装 lvm
yum install -y "/*/lvm"
在知道命令但是不知道软件包名的情况下可以使用yum install -y "/*/命令"来安装
准备好磁盘分区
创建好3个新分区(/dev/sdb1,/dev/sdb2,/dev/sdb3)大小都未1G,并且改变3个新分区类型为8e
命令(输入 m 获取帮助):n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p):
Using default response p
分区号 (1-4,默认 1):
起始 扇区 (2048-41943039,默认为 2048):
将使用默认值 2048
Last 扇区, +扇区 or +size{K,M,G} (2048-41943039,默认为 41943039):+1G
分区 1 已设置为 Linux 类型,大小设为 1 GiB
命令(输入 m 获取帮助):t
已选择分区 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”
准备物理卷
[root@localhost ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
[root@localhost ~]# pvcreate /dev/sdb2
Physical volume "/dev/sdb2" successfully created.
[root@localhost ~]# pvcreate /dev/sdb3
Physical volume "/dev/sdb3" successfully created.
pvdisplay或者pvs:列出当前物理卷信息
[root@localhost ~]# pvdisplay
"/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 eGslCj-Kn2v-gV4T-2z82-MkI7-pwcc-Q0RwN1
创建卷组
vgcreate 组名 物理卷(多个物理卷之间用空格隔开)
[root@localhost ~]# vgcreate vg1 /dev/sdb1 /dev/sdb2
Volume group "vg1" successfully created
vgdisplay或者vgs:查看卷组信息
[root@localhost ~]# vgdisplay
--- 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 1.99 GiB
PE Size 4.00 MiB
Total PE 510
Alloc PE / Size 0 / 0
Free PE / Size 510 / 1.99 GiB
VG UUID 7PRZil-Y1ah-mXzB-AeZd-2NyT-6PH6-3YGIXY
创建逻辑卷
[root@localhost ~]# lvcreate -L 100M -n lv1 vg1
Logical volume "lv1" created.
-L:设定逻辑卷容量
-n:设定逻辑卷名
vg1:不是逻辑卷是从卷组vg1中划分的
格式化逻辑卷
[root@localhost ~]# mkfs.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
25688 inodes, 102400 blocks
5120 blocks (5.00%) reserved for the super user
第一个数据块=1
Maximum filesystem blocks=33685504
13 block groups
8192 blocks per group, 8192 fragments per group
1976 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
挂载逻辑卷
[root@localhost ~]# mount /dev/vg1/lv1 /mnt
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3 18G 2.0G 16G 11% /
devtmpfs 489M 0 489M 0% /dev
tmpfs 494M 0 494M 0% /dev/shm
tmpfs 494M 13M 481M 3% /run
tmpfs 494M 0 494M 0% /sys/fs/cgroup
/dev/sda1 197M 75M 122M 39% /boot
/dev/mapper/vg1-lv1 93M 1.6M 85M 2% /mnt
[root@localhost ~]# ll /dev/vg1/lv1
lrwxrwxrwx. 1 root root 7 7月 9 05:01 /dev/vg1/lv1 -> ../dm-0
[root@localhost ~]# ll /dev/mapper/vg1-lv1
lrwxrwxrwx. 1 root root 7 7月 9 05:01 /dev/mapper/vg1-lv1 -> ../dm-0
/dev/vg1/lv1 和 /dev/mapper/vg1-lv1 都指向同一个设备 ../dm-0
扩容逻辑卷(ext文件系统)
*. 卸载逻辑卷
[root@localhost ~]# umount /mnt
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3 18G 2.0G 16G 11% /
devtmpfs 489M 0 489M 0% /dev
tmpfs 494M 0 494M 0% /dev/shm
tmpfs 494M 13M 481M 3% /run
tmpfs 494M 0 494M 0% /sys/fs/cgroup
/dev/sda1 197M 75M 122M 39% /boot
*. 重新设定逻辑卷容量
[root@localhost ~]# lvresize -L 200M /dev/vg1/lv1
Size of logical volume vg1/lv1 changed from 100.00 MiB (25 extents) to 200.00 MiB (50 extents).
Logical volume vg1/lv1 successfully resized.
*. 检查磁盘错误
[root@localhost ~]# e2fsck -f !$
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
*. 更新逻辑卷信息
[root@localhost ~]# resize2fs !$
resize2fs /dev/vg1/lv1
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/vg1/lv1 to 204800 (1k) blocks.
The filesystem on /dev/vg1/lv1 is now 204800 blocks long.
[root@localhost ~]# mount !$ /mnt
mount /dev/vg1/lv1 /mnt
*. 重新挂载逻辑卷
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3 18G 2.0G 16G 11% /
devtmpfs 489M 0 489M 0% /dev
tmpfs 494M 0 494M 0% /dev/shm
tmpfs 494M 13M 481M 3% /run
tmpfs 494M 0 494M 0% /sys/fs/cgroup
/dev/sda1 197M 75M 122M 39% /boot
/dev/mapper/vg1-lv1 190M 1.6M 175M 1% /mnt
缩容逻辑卷(不支持xfs)
*. 卸载逻辑卷
*. 检查磁盘错误
[root@localhost ~]# 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: 11/49400 files (9.1% non-contiguous), 11884/204800 blocks
*. 更新逻辑卷信息
[root@localhost ~]# resize2fs !$ 150M
resize2fs /dev/vg1/lv1 150M
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/vg1/lv1 to 153600 (1k) blocks.
The filesystem on /dev/vg1/lv1 is now 153600 blocks long.
*. 重新设置逻辑卷容量
[root@localhost ~]# lvresize -L 150M /dev/vg1/lv1
Rounding size to boundary between physical extents: 152.00 MiB.
WARNING: Reducing active logical volume to 152.00 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 200.00 MiB (50 extents) to 152.00 MiB (38 extents).
Logical volume vg1/lv1 successfully resized.
*. 重新挂载逻辑卷
[root@localhost ~]# mount /dev/vg1/lv1 /mnt
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3 18G 2.0G 16G 11% /
devtmpfs 489M 0 489M 0% /dev
tmpfs 494M 0 494M 0% /dev/shm
tmpfs 494M 13M 481M 3% /run
tmpfs 494M 0 494M 0% /sys/fs/cgroup
/dev/sda1 197M 75M 122M 39% /boot
/dev/mapper/vg1-lv1 142M 1.6M 130M 2% /mnt
此处指定的容量必须跟第三步中的容量一致
缩容后的容量不能小于逻辑卷已使用容量
扩容逻辑卷(xfs文件系统)
*. 卸载逻辑卷
*. 将逻辑卷格式化未xfs格式
[root@localhost ~]# mkfs.xfs -f /dev/vg1/lv1
meta-data=/dev/vg1/lv1 isize=256 agcount=4, agsize=9728 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0
data = bsize=4096 blocks=38912, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal log bsize=4096 blocks=853, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
*. 挂载逻辑卷
*. 重新设定逻辑卷容量
[root@localhost ~]# mount !$ /mnt
mount /dev/vg1/lv1 /mnt
[root@localhost ~]# lvresize -L 300M /dev/vg1/lv1
Size of logical volume vg1/lv1 changed from 152.00 MiB (38 extents) to 300.00 MiB (75 extents).
Logical volume vg1/lv1 successfully resized.
[root@localhost ~]# xfs_growfs !$
xfs_growfs /dev/vg1/lv1
meta-data=/dev/mapper/vg1-lv1 isize=256 agcount=4, agsize=9728 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0
data = bsize=4096 blocks=38912, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=853, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 38912 to 76800
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3 18G 2.0G 16G 11% /
devtmpfs 489M 0 489M 0% /dev
tmpfs 494M 0 494M 0% /dev/shm
tmpfs 494M 13M 481M 3% /run
tmpfs 494M 0 494M 0% /sys/fs/cgroup
/dev/sda1 197M 75M 122M 39% /boot
/dev/mapper/vg1-lv1 297M 7.9M 289M 3% /mnt
在重新设定逻辑卷容量后,需要使用 xfs_growfs /dev/vg1/lv1 才能实现扩容
当卷组的容量都被逻辑卷使用完之后,如何实现扩容?