Cloud computing tutorial learning course syllabus courseware: LVM management

Online Capacity Expansion online

Data migration online

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Creating LVM LVM called the Logical Volume Manager

VG expand / shrink

LV dilatation

Online file system expansion and the expansion of 300G + 900G hard disk to do a single disk RAID0 in production

Primary partition (MBR | GPT) ----> Filesystem ----> mount

Logical LVM ----> Filesystem ----> mount

VG is called volume group

extents is called extended block

PE: Physical extent physical expansion 4M 8M 16M 32M 64M -s 8M specified when creating VG

LE: Logical extent logical extension

Sina practical work

Start the Linux operating system in VMware environments, adding a new partition, you need the root account status.

[3.1] The maximum partition fdisk -l / dev / sda3, explained the newly created partition will be sda4

3.2 input [fdisk / dev / sda]

[M] input command line prompt 3.2.1

3.2.2 Enter the command [n] to add a new partition.

3.2.3 Enter the command [p] create a primary partition.

3.2.4 Input [Enter], select the default size, so do not waste space

3.2.5 Input [Enter], select the default start cylinder.

W [3.2.6] input, holding modifications

3.3 Input [reboot] to restart linux, you must reboot, or / dev / sda4 can not be formatted.

3.4 At this point in the / dev / directory to see the new partition such as / dev / sda4

3.5 [mkfs.ext2 / dev / sda4] formatted

3.6 disk4 create a directory in the root directory

3.7 [mount / dev / sda4 / disk4 /] to mount the partition / disk4 /

3.8 modify the vim / etc / fstab file, add [/ dev / sda4 / disk4 ext2 defaults 0 0] line, and save, and boot automatically mount.

Note that with a snapshot of a virtual machine after adding a hard disk to install software

First, create LVM

0. Prepare physical disk

It can be: / dev / sdb / dev / sdc1

[root@server0 ~]# ll /dev/vd{c,d,e}

brw-rw----. 1 root disk 253, 32 Jun 6 17:38 /dev/vdc

brw-rw----. 1 root disk 253, 48 Jun 6 17:38 /dev/vdd

brw-rw----. 1 root disk 253, 64 Jun 6 17:38 /dev/vde

1. pv

[root@server0 ~]# pvcreate /dev/vdd

Physical volume "/dev/vdd" successfully created

[root@server0 ~]# pvscan

PV /dev/vdd lvm2 [2.00 GiB]

Total: 1 [2.00 GiB] / in use: 0 [0 ] / in no VG: 1 [2.00 GiB]

[root@server0 ~]# pvs

PV VG Fmt Attr PSize PFree

/dev/vdd lvm2 a-- 2.00g 2.00g

2. vg

[root@server0 ~]# vgcreate vg1 /dev/vdd

Volume group "vg1" successfully created

[root@server0 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

vg1 1 0 0 wz--n- 2.00g 2.00g

[root@server0 ~]# vgscan

Reading all physical volumes. This may take a while...

Found volume group "vg1" using metadata type lvm2

[root@server0 ~]# vgdisplay vgdisplay datevg

--- Volume group ---

VG Name vg1

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 2.00 GiB

PE Size 4.00 MiB

Total PE 511

Alloc PE / Size 0 / 0

Free PE / Size 511 / 2.00 GiB

VG UUID 7E4tlj-l0a2-ph52-OytH-eaq7-58K6-2S4n8V

3. lv

[root@server0 ~]# lvcreate -l 10 -n lv1 vg1

[root@server0 ~]# lvcreate -L 200M -n lv2 vg1

[root@server0 ~]# lvscan

ACTIVE '/dev/vg1/lv1' [640.00 MiB] inherit

ACTIVE '/dev/vg1/lv2' [256.00 MiB] inherit

4. Create a file system and mount

[root@server0 ~]# mkfs.xfs /dev/vg1/lv1

[root@server0 ~]# mkfs.ext4 /dev/vg1/lv2

[Root @ server0 ~] # mkdir / mnt / LV1 / mnt / LV2

[root@server0 ~]# vim /etc/fstab

/dev/vg1/lv1 /mnt/lv1 xfs defaults 0 0

/dev/vg1/lv2 /mnt/lv2 ext4 defaults 0 0

[root@server0 ~]# mount -a

[root@server0 ~]# df

Filesystem 1K-blocks Used Available Use% Mounted on

/ Dev / folders / vg1-lv1 651,948 32,928 619,020 6% / mnt / lv1

/dev/mapper/vg1-lv2 245671 2062 226406 1% /mnt/lv2

Two, VG management

VG vgextend == == expand

1. pv

[root@server0 ~]# pvcreate /dev/vde

2. vgextend

[root@server0 ~]# vgextend vg1 /dev/vde

Volume group "vg1" successfully extended

[root@server0 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

vg1 2 2 0 wz--n- 3.99g 3.76g

VG vgreduce == == reduced

Usually do first migrating data

1. Review the current usage of PV in the VG

[root@server0 ~]# pvs

PV VG Fmt Attr PSize PFree

/dev/vdd vg1 lvm2 a-- 2.00g 1.76g

/dev/vde vg1 lvm2 a-- 2.00g 2.00g

2. pvmove data to other PV

[root@server0 ~]# pvmove /dev/vdd

/dev/vdd: Moved: 16.7%

/dev/vdd: Moved: 100.0%

[root@server0 ~]# pvs

PV VG Fmt Attr PSize PFree

/dev/vdd vg1 lvm2 a-- 2.00g 2.00g

/dev/vde vg1 lvm2 a-- 2.00g 1.76g

3.vgreduce VG

[root@server0 ~]# vgreduce vg1 /dev/vdd

Removed "/dev/vdd" from volume group "vg1"

[root@server0 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

vg1 1 2 0 wz--n- 2.00g 1.76g

Three, LV dilatation

1. lv expansion

[root@server0 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

vg1 2 2 0 wz--n- 1.88g 1.00g

[root@server0 ~]# lvextend -L 800M /dev/vg1/lv1

[root@server0 ~]# lvextend -L +800M /dev/vg1/lv1

[root@server0 ~]# lvextend -l 15 /dev/vg1/lv1

[root@server0 ~]# lvextend -l +15 /dev/vg1/lv1

=======================================

+50%FREE

=======================================

[root@server0 ~]# lvscan

ACTIVE '/dev/vg1/lv1' [768.00 MiB] inherit

ACTIVE '/dev/vg1/lv2' [512.00 MiB] inherit

2. FS expansion

[root@server0 ~]# df -Th

/dev/mapper/vg1-lv1 xfs 637M 67M 570M 11% /mnt/lv1

/dev/mapper/vg1-lv2 ext4 240M 32M 192M 15% /mnt/lv2

a. xfs

[root@server0 ~]# xfs_growfs /dev/vg1/lv1

b. ext2/3/4

[root@server0 ~]# resize2fs /dev/vg1/lv2

[root@server0 ~]# df -Th

Filesystem Type Size Used Avail Use% Mounted on

/dev/mapper/vg1-lv1 xfs 765M 67M 698M 9% /mnt/lv1

/dev/mapper/vg1-lv2 ext4 488M 32M 429M 7% /mnt/lv2

1.创建pv

[root@localhost ~]# pvcreate /dev/sda5 /dev/sda6

[root@localhost ~]# pvdisplay

[root@localhost ~]# pvs

2.创建vg

[root@localhost ~]# vgcreate vg0 /dev/sda5 /dev/sda6

[root@localhost ~]# vgdisplay

[root@localhost ~]# vgs

3.创建lv

[root@localhost ~]# lvcreate -L 250M -n /dev/vg0/lv0 vg0

[root@localhost ~]# lvdisplay

[root@localhost ~]# lvs

注意:

pv不能跨越vg

lv不能跨越vg

系统中可以创建多个vg

vg中可以创建多个lv

删除lvm

1.umount /dev/vg0/lv0

2.[root@localhost ~]# lvremove /dev/vg0/lv0

3.[root@localhost ~]# vgremove vg0

4.[root@localhost ~]# pvremove /dev/sda{5,6,8}

企业中的应用 如果根分区满了 怎么做？？

df -h 查看

pvcreate /dev/sdb

vgs

vgextend centos /dev/sdb

lvscan

lvextend -L +5G /dev/centos/root

df -T

xfs_growfs /dev/centos/root

df -Th

lvextend -L +5G /dev/centos/root

xfs_growfs /dev/centos/root

df -h

准备3块硬盘 可不分区 思路---PV----VG---LV

lsblk

##创建PV

pvcreate /dev/sdb

##查看当前PV

pvscan

pvs

vgcreate datavg /dev/sdb （datavg是起的名字）

vgscan

pvscan ##得到回显 pv/dev/sdb 加入到了VG datevg 容量XXfree

#创建LV

lvcreate -L 200M -n lv1 datavg -L（指定lv的大小） 指定为200m lv1为起的名字 从datevg里创建

lvcreate -L 300M -n lv2 datavg

lvscan ## 得到回显 /dev/datevg/lv1 200m

/dev/datevg/lv2 300m

这时候看lsblk 去看看/dev/sdb？？？？

##格式化，创建文件系统挂载

mkfs.xfs /dev/datevg/lv1

mkfs.ext4 /dev/datevg/lv2

mkdir /mnt/lv1 /mnt/lv2

挂载

mount /dev/datevg/lv1 /mnt/lv1

mount /dev/datevg/lv2 /mnt/lv2

mount -a

df -h （df-Th） 加上TYPE 类型

LVM完成

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扩大VG

vgs

pvcreate /dev/sdc 先变成PV

vgextend datevg /dev/sdc 查看pvscan

vgs free变大 实验成功

继续扩容

pvcreate /dev/sdd

vgextend datevg /dev/sdd

继续查看 VFree 继续变大

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减小VG 数据迁移 ！！！！！！！！！！！！！！！！！！！！！！！！！！！！！

pvs 查看

pvmove /dev/sdb /dev/sdc 将sdb数据仍到sdc

vgreduce datevg /dev/sdb

pvscan

查看变化。数据迁移完成

注意:

pv不能跨越vg

lv不能跨越vg

系统中可以创建多个vg

vg中可以创建多个lv