Cloud Computing Learning Route course syllabus Courseware: LVM Management

Online expansion of online

Data migration online

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Creating a LVM LVM is called logical volume management

VG expand / shrink

LV capacity expansion

Expansion of file system, online expansion and single disk RAID0 of 300G+900G hard disk in production

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

Logical volume LVM-> Filesystem-> mount

VG is called volume group

Extents is called extension block

PE: Physical extent physical extension 4m 8m 16m 32m 64m specify-s 8m when creating VG

LE: Logical extent logical extension

In the actual work of Sina

Starting the Linux operating system in VMware environment and adding a new partition requires the identity of a root account.

3.1 [fdisk-l] the maximum partition is / dev/sda3, indicating that the newly created partition will be sda4

3.2 enter [fdisk / dev/sda]

3.2.1 enter [m] at the command line prompt

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

3.2.3 enter the command [p] to create the primary partition.

3.2.4 enter [enter] and select the default size, so that no space is wasted

3.2.5 enter "enter" and select the default start cylinder.

3.2.6 enter [w] to keep the modification

Enter [reboot] to restart linux, which must be reboot, otherwise / dev/sda4 cannot be formatted.

3.4 only in the / dev/ directory can you see the new partition such as / dev/sda4

3.5 [mkfs.ext2 / dev/sda4] formatting

3.6 create a disk4 directory under the root directory

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

3.8 modify the / etc/fstab file in vim, add a line [/ dev/sda4 / disk4 ext2 defaults 00], and save it to realize automatic boot mount.

Note that a virtual machine with a snapshot needs to add a hard disk after installing software

First, create a LVM

Prepare the physical disk

It could be: / dev/sdb / dev/sdc1

[root@server0 ~] # ll / dev/vd {cmeno dpene}

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

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 muri-2.00g 2.00g

Vg

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

Volume group "vg1" successfully created

[root@server0 ~] # vgs

VG # PV # LV # SN Attr VSize VFree

Vg1 1 00 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-ph62-OytH-eaq7-58K6-2S4n8V

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

Create a file system and mount it

[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/mapper/vg1-lv1 651948 32928 619020 6 / mnt/lv1

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

II. VG management

= = expand VG vgextend==

Pv

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

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

= = reduce VG vgreduce==

Data migration is usually done first.

1. View the usage of PV in the current VG

[root@server0 ~] # pvs

PV VG Fmt Attr PSize PFree

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

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

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 muri-2.00g 2.00g

/ dev/vde vg1 lvm2 a muri-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

III. Expansion of LV

Lv capacity 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

FS capacity expansion

[root@server0 ~] # df-Th

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

/ dev/mapper/vg1-lv2 ext4 240M 32m 192 M 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. Create pv [root@localhost ~] # pvcreate / dev/sda5 / dev/sda6 [root@localhost ~] # pvdisplay [root@localhost ~] # pvs2. Create vg [root@localhost ~] # vgcreate vg0 / dev/sda5 / dev/sda6 [root@localhost ~] # vgdisplay [root@localhost ~] # vgs3. Create lv [root@localhost ~] # lvcreate-L 250M-n / dev/vg0/lv0 vg0 [root@localhost ~] # lvdisplay [root@localhost ~] # lvs Note: pv cannot span vglv, can not span vg system, can create multiple vgvg, can create multiple lv to delete lvm1.umount / dev/vg0/lv02. [root@localhost ~] # lvremove / dev/vg0/lv03. [root@localhost ~] # vgremove vg04. [root@localhost ~] # pvremove / dev/sda {5Power6 8} what should an application in an enterprise do if the root partition is full? Df-h View pvcreate / dev/sdbvgsvgextend centos/ dev/sdblvscanlvextend-L + 5G / dev/centos/rootdf-Txfs_growfs / dev/centos/rootdf-Thlvextend-L + 5G / dev/centos/rootxfs_growfs / dev/centos/rootdf-h prepare three hard drives but not partition ideas-PV----VG---LVlsblk## create PVpvcreate / dev/sdb## to view the current PVpvscanpvsvgcreate datavg / dev/sdb (datavg is the name) vgscanpvscan # # get echo pv/ Dev/sdb added to VG datevg capacity XXfree# create LVlvcreate-L 200m-n lv1 datavg-L (specify the size of lv) specify 200m lv1 name from datevg create lvcreate-L 300m-n lv2 datavglvscan # # get echo / dev/datevg/lv1 200m/dev/datevg/lv2 300m look at lsblk to see / dev/sdb???? # # formatting Create file system mount mkfs.xfs / dev/datevg/lv1mkfs.ext4 / dev/datevg/lv2mkdir / mnt/lv1 / mnt/lv2 mount mount / dev/datevg/lv1 / mnt/lv1mount / dev/datevg/lv2 / mnt/lv2mount-adf-h (df-Th) plus TYPE type LVM complete # # expand VGvgspvcreate / dev/sdc first to PVvgextend datevg / dev/sdc to view pvscanvgs free enlargement experiment successfully continue to expand pvcreate / dev/sddvgextend datevg / dev/sdd continue to view VFree continue to grow # # reduce VG data migration! Pvs View pvmove / dev/sdb / dev/sdc drop the sdb data to sdcvgreduce datevg / dev/sdbpvscan to see the changes. Data migration completed Note: pv cannot span vglv can not span vg system can create multiple vgvg can create multiple lv