Linux中创建LVM详细步骤
Linux中创建LVM详细步骤
1 什么事逻辑卷管理器LVM
LVM: 将几个物理分区通过软件组合在一起，看起来像是独立的大硬盘，而要用这块大硬盘，就要将它分成可以使用的分区，然后格式化，挂载等
PV物理卷：将物理磁盘或物理分区初始化成LVM能用的物理卷，分区中的类型是8e:Linux LVM
VG逻辑卷组：将一个或者多个PV组合成一个大的磁盘，将其称之为组
LV逻辑卷：从VG中分割出来的分区，称为LV，LV被用来格式化后，进行挂载，设备代为：
/dev/vgname/lvname
2 LVM结构图
演示实验：
1 创建一个100M的PV
系统中磁盘状态：
[root@desktop0 /]# fdisk -l Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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
从sdb硬盘中添加一个分区：用作pv
[root@desktop0 /]#
[root@desktop0 /]# fdisk /dev/sdb
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): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x541e3b32
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):
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): +300M
Partition 1 of type Linux and of size 300 MiB is set
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x541e3b32
Device Boot Start End Blocks Id System
/dev/sdb1 2048 616447 307200 83 Linux
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/sdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x541e3b32
Device Boot tart End Blocks Id System
/dev/sdb1 2048 616447 307200 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@desktop0 /]# partprobe
[root@desktop0 /]#
分区后：
[root@desktop0 /]# fdisk -l Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x541e3b32 Device Boot Start End Blocks Id System /dev/sdb1 2048 616447 307200 8e Linux LVM
创建pv物理卷：
[root@desktop0 /]# [root@desktop0 /]# pvcreate /dev/sdb1 Physical volume "/dev/sdb1" successfully created [root@desktop0 /]#
查看pv:
[root@desktop0 /]# pvdisplay "/dev/sdb1" is a new physical volume of "300.00 MiB" --- NEW Physical volume --- PV Name /dev/sdb1 VG Name PV Size 300.00 MiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID lUYnLJ-u6In-GAIA-b2YG-JHuX-AG6F-A4yVMR
创建vg逻辑卷组：
[root@desktop0 /]# vgcreate myvg /dev/sdb1 Volume group "myvg" successfully created [root@desktop0 /]# vgdisplay --- Volume group --- VG Name myvg 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 296.00 MiB PE Size 4.00 MiB Total PE 74 Alloc PE / Size 0 / 0 Free PE / Size 74 / 296.00 MiB VG UUID nyc2Z4-zihI-jT9T-mvcF-ff8a-3Y0r-5Gkn7r
创建lv逻辑卷：mylv1:
[root@desktop0 /]# man lvcreate [root@desktop0 /]# lvcreate -L 100M -n mylv1 myvg Logical volume "mylv1" created
查看是否创建成功：
[root@desktop0 /]# lvdisplay --- Logical volume --- LV Path /dev/myvg/mylv1 LV Name mylv1 VG Name myvg LV UUID VEdiDz-OLEH-Yua4-AQN9-2W26-nojO-KlpLaE LV Write Access read/write LV Creation host, time desktop0.example.com, 2015-05-13 04:00:22 -0400 LV Status available # open 0 LV Size 100.00 MiB Current LE 25 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0 [root@desktop0 /]# lvscan ACTIVE '/dev/myvg/mylv1' [100.00 MiB] inherit [root@desktop0 /]#
查看mylv1分区是否成功：
[root@desktop0 /]# fdisk -l ……………… Disk /dev/mapper/myvg-mylv1: 104 MB, 104857600 bytes, 204800 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
格式化为ext3文件系统：
[root@desktop0 /]# mkfs.ext3 /dev/myvg/mylv1 mke2fs 1.42.9 (28-Dec-2013) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=0 blocks, Stripe width=0 blocks 25688 inodes, 102400 blocks 5120 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=67371008 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: done Writing inode tables: done Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done
挂载/dev/myvg/mylv1 to /mnt/mylvtest:
[root@desktop0 /]# mkdir /mnt/mylvtest [root@desktop0 /]# mount /dev/myvg/mylv1 /mnt/mylvtest/
查看挂载：
[root@desktop0 /]# mount | grep "/mnt/mylvtest" /dev/mapper/myvg-mylv1 on /mnt/mylvtest type ext3 (rw,relatime,seclabel,data=ordered) [root@desktop0 /]#
查看挂载情况：
[root@desktop0 /]# df -hT Filesystem Type Size Used Avail Use% Mounted on /dev/sda1 xfs 10G 3.1G 7.0G 31% / devtmpfs devtmpfs 899M 0 899M 0% /dev tmpfs tmpfs 914M 140K 914M 1% /dev/shm tmpfs tmpfs 914M 17M 897M 2% /run tmpfs tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/mapper/myvg-mylv1 ext3 93M 1.6M 85M 2% /mnt/mylvtest
[root@desktop0 /]#
[root@desktop0 /]# cd /mnt/mylvtest/
[root@desktop0 mylvtest]# ls
lost+found
[root@desktop0 mylvtest]# touch {1..4}.txt
[root@desktop0 mylvtest]# ls
1.txt 2.txt 3.txt 4.txt lost+found
[root@desktop0 mylvtest]# pwd
/mnt/mylvtest
------------成功创建一个100M的lv,并且挂载在/mnt/mylvtest下-----------------
-=*************扩容lv卷***********************
卸载挂载：
[root@desktop0 /]# umount /dev/myvg/mylv1
增加100M:
[root@desktop0 mylvtest]# lvextend -L +100M /dev/myvg/mylv1 Extending logical volume mylv1 to 200.00 MiB Logical volume mylv1 successfully resized
验证：
[root@desktop0 mylvtest]# lvscan ACTIVE '/dev/myvg/mylv1' [200.00 MiB] inherit
验证：发觉没有刷新
[root@desktop0 mylvtest]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 10G 3.1G 7.0G 31% / devtmpfs 899M 0 899M 0% /dev tmpfs 914M 140K 914M 1% /dev/shm tmpfs 914M 17M 897M 2% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/mapper/myvg-mylv1 93M 1.6M 85M 2% /mnt/mylvtest
刷新lv: resize2fs
[root@desktop0 mylvtest]# resize2fs /dev/myvg/mylv1 ##刷新lv resize2fs 1.42.9 (28-Dec-2013) Filesystem at /dev/myvg/mylv1 is mounted on /mnt/mylvtest; on-line resizing required old_desc_blocks = 1, new_desc_blocks = 1 The filesystem on /dev/myvg/mylv1 is now 204800 blocks long.
挂载：
[root@desktop0 /]# mount /dev/myvg/mylv1 /mnt/mylvtest
验证：已刷新
[root@desktop0 mylvtest]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 10G 3.1G 7.0G 31% / devtmpfs 899M 0 899M 0% /dev tmpfs 914M 140K 914M 1% /dev/shm tmpfs 914M 17M 897M 2% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/mapper/myvg-mylv1 190M 1.6M 178M 1% /mnt/mylvtest [root@desktop0 mylvtest]#
-----------------------------------------------------
************************缩减lv卷容量****************
卸载挂载：
[root@desktop0 /]# umount /dev/myvg/mylv1
校验分区：
[root@desktop0 mnt]# e2fsck -f /dev/myvg/mylv1 e2fsck 1.42.9 (28-Dec-2013) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information /dev/myvg/mylv1: 11/55296 files (0.0% non-contiguous), 12900/217088 blocks
指定缩小后的大小：
[root@desktop0 mnt]# resize2fs /dev/myvg/mylv1 100M resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/myvg/mylv1 to 102400 (1k) blocks. The filesystem on /dev/myvg/mylv1 is now 102400 blocks long.
缩小lv容量：
[root@desktop0 mnt]# lvreduce -L 100M /dev/myvg/mylv1 WARNING: Reducing active logical volume to 100.00 MiB THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce mylv1? [y/n]: Y Reducing logical volume mylv1 to 100.00 MiB Logical volume mylv1 successfully resized [root@desktop0 mnt]#
验证：
[root@desktop0 mnt]# lvdisplay --- Logical volume --- LV Path /dev/myvg/mylv1 LV Name mylv1 VG Name myvg LV UUID TmZGYo-Xm6P-RgyQ-w9bl-JfCh-GLbv-bbzLTK LV Write Access read/write LV Creation host, time desktop0.example.com, 2015-05-13 07:37:48 -0400 LV Status available # open 0 LV Size 100.00 MiB Current LE 25 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0 [root@desktop0 mnt]#
重新挂载：
[root@desktop0 mnt]# mount /dev/myvg/mylv1 /mnt/mylvtest/ 验证： [root@desktop0 mnt]# df -hT Filesystem Type Size Used Avail Use% Mounted on /dev/sda1 xfs 10G 3.1G 7.0G 31% / devtmpfs devtmpfs 899M 0 899M 0% /dev tmpfs tmpfs 914M 140K 914M 1% /dev/shm tmpfs tmpfs 914M 17M 897M 2% /run tmpfs tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/mapper/myvg-mylv1 ext3 93M 1.6M 85M 2% /mnt/mylvtest