Shulou(Shulou.com)06/01 Report--

How to analyze linux LVM, I believe that many inexperienced people are at a loss about it. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

1. Create and delete steps

1) create: linux partition-- > pv-- > vg-- > lv-- > fs-- > mount

2) Delete: umount-- > lv-- > vg-- > pv-- > linux partition

2.linux partition

In linux, we often partition disks by fdisk. But for disks above 2T, you have to use the parted command to partition.

1) GPT disk and MBR disk

Disks that use GUID partition tables are often called GPT disks. Unlike the original MBR disks, GPT disks do not have the limit of four primary partitions and can be set up to 128partitions. GPT disks are usually partitioned with the parted command.

2) Operation

-- View disk partitions

[root] # fdisk-l

-- partitioning sda

[root] # parted / dev/sda

-- rescan the partition

[root] # partprobe

-- after viewing the partition

[root] # fdisk-l

3 PV Management

1) create PV (pvcreate)

[root] # pvcreate / dev/sda3

2) View PV (pvs or pvscan)

[root] # pvs

[root] # pvscan

3) View PV details (pvdiskplay)

[root] # pvdisplay / dev/sda3

4) Delete PV (pvremove)

[root] # pvremove / dev/sda3

4.VG management

1) create VG (vgcreate)

Syntax: vgcreate [- s] vg0 / dev/sdb {1meme 2jue 3.}

-- among them:

-s: specify the size of the expansion block (PE). The default is 4MB. It can be 8m _ pr _ 16m _ 32m _ 32m _ 64m ·L _ 16G, but a LV can have up to 65532 expansion blocks.

Vg0: the newly created VG name.

/ dev/sdb {1 PV,PV 2pm 3.}: writable multiple CDs are separated by spaces.

[root] # vgcreate-s 16m testvg / dev/sda3

2) View VG (vgs or vgscan)

[root] # vgs

[root] # vgscan

3) View VG details (vgdisplay)

[root] # vgdisplay testvg

4) vg extension (vgextend)

-- using fdisk to create a new partition

[root] # fdisk / dev/sda

Command (m for help): n

Select (default e): e

Selected partition 4

First sector (117187501-209715199, default 117188608):

Last sector, + sectors or + size {KMagne Mpeng} (117188608-209715199, default 209715199):

Command (m for help): P

Command (m for help): n

All primary partitions are in use

Adding logical partition 5

First sector (117190656-209715199, default 117190656):

Using default value 117190656

Last sector, + sectors or + size {KMagne Mpeng} (117190656-209715199, default 209715199): + 20G

-- change partition type to lvm

Command (m for help): t

Partition number (1-5, default 5):

Hex code (type L to list all codes): 8e

Command (m for help): W

-- check partition again

[root] # fdisk-l

-- notify the system of core partition changes

[root] # partprobe

-- create a PV

[root] # pvcreate / dev/sda5

-- extended vg

[root] # vgextend testvg / dev/sda5

5) vg reduction

[root] # vgreduce testvg / dev/sda5

6) vg deletion

[root] # vgremove testvg

5 Management of LV

1) creation of LV (lvcreate)

Syntax 1:lvcreate-L 512m-n data testvg-L 512m

-- among them

Set the size of the LV to 512m.

-n data: set the name of LV to data.

[root] # lvcreate-L 510m-n date testvg

Syntax 2:lvcreate-l 32-n data testvg-l 32

-- among them

The resulting LV uses 32 extension blocks, and the LV size = 32*PE (default 4m) is 128m.

-the name of n data:LV. Vg0: the setting is the LV generated by that VG.

Vg0: the setting is the LV generated by that VG.

[root] # lvcreate-l 10-n data testvg

2) View LV (lvs or lvscan)

[root] # lvs

3) View LV details (lvdisplay)

[root] # lvdisplay testvg

4) format LV (mkfs.ext3)

[root] # mkfs.ext3 / dev/testvg/data

5) increase LV (lvextend)

[root] # lvextend-L + 160m / dev/testvg/data

-- among them

Resize2fs is required for it to take effect immediately.

[root] # resize2fs / dev/testvg/data

6) reduce LV size (lvreduce)

[root] # lvreduce-L 160m / dev/testvg/data

[root] # resize2fs / dev/testvg/data

7) Delete LV (lvremove/vg/lv)

[root] # lvremove / dev/testvg/date

6) Mount the file system

[root] # mkfs.ext3 / dev/testvg/data

[root] # mkdir / data

[root] # mount / dev/testvg/data / data

7 lvm Snapshot

1) create a snapshot

Syntax: lvcreate-l 64-s-n databackup / dev/testvg/data

-- among them

-l 64: specifies 64 extension blocks for the snapshot.

Total capacity = 64 * single expansion block size

-n databackup: the name of the snapshot generated.

/ dev/testvg/data: source LV name.

[root] # lvcreate-L 160m-s-n databackup / dev/testvg/data

2) View LVM Snapshot (lvscan)

[root] # lvscan

3) View snapshot details (lvdisplay)

[root] # lvdisplay / dev/testvg/data

4) deletion of snapshots (lvremove)

[root] # lvremove / dev/testvg/databackup

After reading the above, do you know how to parse linux LVM? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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