Create a logical volume using LVM - Elastic Compute Service

The Logical Volume Manager (LVM) lets you combine data disks or partitions into a single Storage Pool that can be dynamically expanded.

How it works

Creating a logical volume (LV) involves four main steps:

Create a physical volume (pvcreate): Mark a data disk for use by LVM.
Create a volume group (vgcreate): Combine the marked Physical Volumes (PV) into a Storage Pool.
Create a LV (lvcreate): Carve out a logical partition of a specific size from the Volume Group (VG).
Create and mount a file system (mkfs & mount): Create a file system and a mount point (access path) for the LV.

As shown in the diagram, two 40 GiB data disks (/dev/vdb and /dev/vdc) are initialized as PV and added to a VG named vg_01, forming an 80 GiB Storage Pool. A 55 GiB LV named lv01 is then carved out from the pool for use.

Procedure

Step 1: Create a PV

Important

Creating a PV erases all data on the data disk. Ensure the data disk is empty or you have backed up all necessary data.

Log on to the Elastic Compute Server (ECS) instance.
1. Go to ECS console - Instance. In the top navigation bar, select the target region and resource group.
2. Go to the details page of the target instance. Click Connect and select Workbench. Follow the on-screen prompts to log on and open the terminal.
Install the LVM tool.
Alibaba Cloud Linux and CentOS
```
sudo yum install -y lvm2
```
Debian and Ubuntu
```
sudo apt-get install -y lvm2
```

To find the target device names, run the sudo lsblk -f command.

sudo lsblk -f

NAME   FSTYPE LABEL UUID                                 MOUNTPOINT
vda                                                      
├─vda1                                                   
├─vda2 vfat         7938-FA03                            /boot/efi
└─vda3 ext4   root  33b46ac5-7482-4aa5-8de0-60ab4c3a4c78 /
vdb                                                      
vdc                                                      
vdd                                                      
└─vdd1

If the FSTYPE column is not empty, the device has already been initialized and cannot be used as a PV.
If the FSTYPE column is empty:
- If the device does not have partitions, the target device name is the same as the device name. In the example, the target device name for data disk vdb is vdb, and for data disk vdc it is vdc.
- If the device has partitions, the target device name is the name of the desired partition. In the example, the target device name for data disk vdd is vdd1.

Create the PVs.
Separate device names with spaces. Replace <target_device_name> with the device names you found in the previous step.
```
sudo pvcreate /dev/<target device name>.../dev/<target device name>
```
For example, to use vdb and vdc as target devices, run sudo pvcreate /dev/vdb /dev/vdc. This command creates two 40 GiB PVs.
Output including successfully created confirms the operation was successful.

Step 2: Create a VG

Create the VG.
Specify a custom <vg_name> and replace <target_device_name> with the device names from Step 1.
```
sudo vgcreate <vg_name> /dev/<target device name>.../dev/<target device name>
```
For example, to create a VG named vg_01 and add vdb and vdc to it, run: sudo vgcreate vg_01 /dev/vdb /dev/vdc.
If the output includes successfully created, the VG was created successfully.
Check the VG's free space.
Run the sudo vgs command. Note the value in the VFree column, which indicates the remaining available capacity.
```
sudo vgs
```

Step 3: Create a LV

Create the LV.
```
sudo lvcreate -L <lv_size> -n <lv_name> <vg_name>
```
For example, to create an LV named lv01 with a size of 55 GiB from the VG vg_01, run: sudo lvcreate -L 55g -n lv01 vg_01.
Parameter
Description
<lv_size>
Must be less than the VG's available free space.
<lv_name>
A custom name for the new LV.
<vg_name>
The name of the VG you created.
If the output is Logical volume "<lv_name>" created, the LV was created successfully.

View the LV information.

Run the sudo lvdisplay command. Note the LV Path. You will need it later to create the file system.

sudo lvdisplay

  --- Logical volume ---
  LV Path                /dev/vg_01/lv01
  LV Name                lv01
  VG Name                vg_01
  LV UUID                NgcCdz-efSY-vCrm-E35b-Dg6p-LNYq-xxxxxx
  LV Write Access        read/write
  LV Creation host, time iZbp13kehgn0kh64txxxxxx, 2025-09-15 16:57:21 +0800
  LV Status              available
  # open                 0
  LV Size                55.00 GiB
  Current LE             14080
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           252:0

In this example, the LV Path for lv01 is /dev/vg_01/lv01.

Step 4: Create and mount a file system

Create a file system.
The ext4 file system is better suited for handling small files than xfs.
ext4
1. Create an ext4 file system.
  Replace <lv_path> with the LV Path you obtained in Step 3.
```
sudo mkfs -t ext4 <lv_path>
```
  In our example, the LV Path is /dev/vg_01/lv01, so you would run sudo mkfs -t ext4 /dev/vg_01/lv01.
2. Verify the creation.
  Run sudo lsblk -f. If the FSTYPE for the target device is ext4, the setup was successful.
xfs
1. Install the xfsprogs tool.
  - For Alibaba Cloud Linux and CentOS:
    sudo yum install -y xfsprogs
  - For Debian and Ubuntu:
    sudo apt-get install -y xfsprogs
2. Create an xfs file system.
  Create an xfs file system.Replace <lv_path> with the LV Path you obtained in Step 3.
```
sudo mkfs -t xfs <lv_path>
```
  In our example, the LV Path is /dev/vg_01/lv01, so you would run sudo mkfs -t xfs /dev/vg_01/lv01.
3. Verify the creation.
  Run sudo lsblk -f. If the FSTYPE for the target device is xfs, the setup was successful.

Create a mount point and mount the file system.

sudo mkdir <mount point> && sudo mount <lv_path> <mount point>

Parameter	Description
`<lv_path>`	The LV Path obtained when you created the LV.
`<mount point>`	A custom, empty directory path that starts with `/`. Mounting to a non-empty directory hides its original contents, which can disrupt services and make the original files inaccessible.

For example, to mount the LV at /dev/vg_01/lv01 to a new directory /mnt/lv01, run: sudo mkdir /mnt/lv01 && sudo mount /dev/vg_01/lv01 /mnt/lv01.

Check if the file system is mounted successfully.
Run the sudo lsblk command. If the target device has a value in the MOUNTPOINT column, the file system is mounted successfully.
Important
This mount is temporary and will be lost after a reboot. To ensure the mount persists after a reboot, we recommend configuring automatic mounting at startup.

FAQ

How do I add a new PV to an existing VG?
1. Log on to the ECS instance.
  1. Go to ECS console - Instance. In the top navigation bar, select the target region and resource group.
  2. On the instance details page, click Connect and select Workbench.
2. View PV and VG information.
  1. View PVs.
    Run sudo pvdisplay. Find and record the PV name from the PV Name field.
  2. View existing VGs.
    Run sudo vgs. Find and record the VG name from the VG field.
3. Add other created PVs.
  Replace <vg_name> and <pv_name> with the information from the previous step.
```
sudo vgextend <vg_name> <pv_name>...<pv_name>
```
Why do I get a "404 Not Found" error when installing tools?
Cause: This error occurs because CentOS 6 and Debian 9/10/11 have reached their End-of-Life (EOL), and their default package repositories are no longer active.
Solution: You must update your system's repository source to point to an official archive server. After updating the source, you can run the installation command again.
- For CentOS 6, follow the guide to switch the CentOS repository source.
- For Debian 9/10/11, follow the guide to switch the Debian repository source.
What does my LV mount information is missing after a reboot, and how do I fix it?
Cause: The volume was mounted manually, but an entry for it was not added to the /etc/fstab file. This file manages which file systems are automatically mounted at boot.
Solution:
1. First, mount the file system manually again if it is not already mounted, as described in Step 4.
2. To make the mount permanent, you must configure automatic mounting at startup by adding an entry for the volume to your /etc/fstab file.
When running lvcreate, why do I get the error "Volume group "vg01" has insufficient free space (23038 extents): 51200 required." when creating a LV?
Cause: This error means the size you specified for the new LV (-L <lv_size>) is larger than the available free space in the vg_01.
Solution:
1. Check the available space in your VG by running sudo vgs and noting the value in the VFree column.
2. Re-run the lvcreate command with a size that is less than or equal to the available free space.

Reference

If your LV runs out of space, you can use the lvextend command to extend the LV.

Elastic Compute Service:Create a logical volume

How it works

Procedure

Step 1: Create a PV

Alibaba Cloud Linux and CentOS

Debian and Ubuntu

Step 2: Create a VG

Step 3: Create a LV

Step 4: Create and mount a file system

ext4

xfs

FAQ

How do I add a new PV to an existing VG?

Add other created PVs.

Why do I get a "404 Not Found" error when installing tools?

What does my LV mount information is missing after a reboot, and how do I fix it?

When running `lvcreate`, why do I get the error "Volume group "vg01" has insufficient free space (23038 extents): 51200 required." when creating a LV?

Reference

Parameter	Description
`<lv_size>`	Must be less than the VG's available free space.
`<lv_name>`	A custom name for the new LV.
`<vg_name>`	The name of the VG you created.

How it works

Procedure

Step 1: Create a PV

Alibaba Cloud Linux and CentOS

Debian and Ubuntu

Step 2: Create a VG

Step 3: Create a LV

Step 4: Create and mount a file system

ext4

xfs

FAQ

How do I add a new PV to an existing VG?

Add other created PVs.

Why do I get a "404 Not Found" error when installing tools?

What does my LV mount information is missing after a reboot, and how do I fix it?

When running lvcreate, why do I get the error "Volume group "vg01" has insufficient free space (23038 extents): 51200 required." when creating a LV?

Reference

When running `lvcreate`, why do I get the error "Volume group "vg01" has insufficient free space (23038 extents): 51200 required." when creating a LV?