逻辑卷管理LVM
一 创建逻辑卷
1准备分区或硬盘
这里使用/dev/sdb、/dev/sdc两块硬盘和/dev/sda9、/dev/sda10两个分区,大小都为1G,磁盘有限,我也不想这么抠的。
添加分区/dev/sda9、/dev/sda10
[root@centos7 ~]# 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
All primary partitions are in use
Adding logical partition 9
First sector (31885312-41943039, default 31885312):
Using default value 31885312
Last sector, +sectors or +size{K,M,G} (31885312-41943039, default 41943039): +1G
Partition 9 of type Linux and of size 1 GiB is set
注意,要修改分区类型为Linux LVM
Command (m for help): t
Partition number (1-9, default 9): 8e
Partition number (1-9, default 9): 9
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help):
同样的方法创建/dev/sda10。
[root@centos7 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda9 8:9 0 1G 0 part
└─sda10 8:10 0 1G 0 part
sdb 8:16 0 1G 0 disk
sdc 8:32 0 1G 0 disk
2 创建PV(物理卷)
命令格式为:pvcreate DEVICE,可以一次创建一个设备,也可以一次创建多个设备。
查看物理卷命令:pvdisplay(查看详细信息)、pvs(查看简易信息)
[root@centos7 ~]# pvcreate /dev/sda9
Physical volume "/dev/sda9" successfully created.
[root@centos7 ~]# pvcreate /dev/sda10 /dev/sdb /dev/sdc
Physical volume "/dev/sda10" successfully created.
Physical volume "/dev/sdb" successfully created.
Physical volume "/dev/sdc" successfully created.
查看物理卷,看到已经成功创建。
[root@centos7 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda10 lvm2 --- 1.00g 1.00g
/dev/sda9 lvm2 --- 1.00g 1.00g
/dev/sdb lvm2 --- 1.00g 1.00g
/dev/sdc lvm2 --- 1.00g 1.00g
3 创建卷组(VG)
命令格式为:vgcreate -s PE VGNAME(vg名) DEVICE(设备名)
-s :指定物理扩展块大小 既就是PE的大小
查看命令:vgs、vgdisplay
[root@centos7 ~]# vgcreate -s 16M vg0 /dev/sda9 /dev/sda10 /dev/sdb /dev/sdc
Volume group "vg0" successfully created
查看一下
[root@centos7 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg0 4 0 0 wz--n- 3.94g 3.94g
再来看下详细信息
[root@centos7 ~]# vgdisplay
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 4
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 4
Act PV 4
VG Size 3.94 GiB
PE Size 16.00 MiB
Total PE 252
Alloc PE / Size 0 / 0
Free PE / Size 252 / 3.94 GiB
VG UUID qmoIMg-5wQR-GKCS-dpq9-HLrt-zVIi-JBC9ZX
一切都复合预期,大小约为4G,正好是两个分区和两个硬盘之和。
4创建逻辑卷(LV)
命令格式为:lvcreate -n LVNAME(指定LV名) -L SIZE(指定LV的大小) vg0(要使用的VG)
-l 指定PE 大小
查看命令(类似PV、VG):lvs、lvdisplay
[root@centos7 ~]# lvcreate -n lv0 -L 3G vg0
Logical volume "lv0" created.
创建成功,查看一下
[root@centos7 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv0 vg0 -wi-a----- 3.00g
再看下详细信息
[root@centos7 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/vg0/lv0
LV Name lv0
VG Name vg0
LV UUID 622i7m-uy6s-3nZI-8xSb-sxrR-cZzz-C9pwkd
LV Write Access read/write
LV Creation host, time centos7.3.loacl, 2017-04-25 16:25:13 +0800
LV Status available
# open 0
LV Size 3.00 GiB
Current LE 192
Segments 4
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
可以确定已经成功创建。
现在就可以把/dev/vg0/lv0当做一块硬盘使用了。
现在看一下磁盘信息,已经发生了变化。
[root@centos7 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
fd0 2:0 1 4K 0 disk
sda 8:0 0 20G 0 disk
├─sda9 8:9 0 1G 0 part
│ └─vg0-lv0 253:0 0 3G 0 lvm
└─sda10 8:10 0 1G 0 part
└─vg0-lv0 253:0