Linux Cloud Server Storage Expansion: Methods and Step‑by‑Step Guide

This article explains how to expand storage on Linux cloud servers (Tencent Cloud CVM with CBS) when business data grows and the original disk space becomes insufficient. It first describes the environment (CentOS 7.6, Tencent Cloud CVM with CBS) and then introduces three ways to use cloud disks in Linux: bare device (no partition), MBR partition, and GPT partition.

1. Storage Expansion Overview

Cloud disks can be expanded on demand, but there are two limitations: system disks cannot be expanded, and local disks (host‑attached) cannot be expanded. The article focuses on CBS cloud disks.

2. Bare Device Disk Usage

Creating a filesystem directly on the raw block device (e.g., /dev/vdb ) without any partition simplifies management and supports online expansion.

Typical steps:

[root@VM_0_89_centos ~]# fdisk -l
Disk /dev/vdb: 107.4 GB, 107374182400 bytes, 209715200 sectors   # data disk
[root@VM_0_89_centos ~]# mkfs.ext4 /dev/vdb    # create ext4 filesystem
[root@VM_0_89_centos ~]# blkid /dev/vdb
/dev/vdb: UUID="7fb2c90a-fcd1-472c-b07c-8a20e2e9a436" TYPE="ext4"
# add to /etc/fstab
UUID="7fb2c90a-fcd1-472c-b07c-8a20e2e9a436" /data ext4 defaults 0 0
# mount
[root@VM_0_89_centos ~]# mount -a
[root@VM_0_89_centos ~]# df -h

After expanding the cloud disk in the console, the filesystem can be enlarged online with resize2fs (ext4) or xfs_growfs (xfs).

3. MBR Disk Partition

Suitable for disks < 2 TB. The process includes creating a primary partition with fdisk , formatting it (ext4 or xfs), adding an entry to /etc/fstab , and mounting.

[root@VM_0_89_centos ~]# fdisk /dev/vdb
Command (m for help): n
Partition type: p (primary)
Partition number: 1
First sector: 2048
Last sector: +100G
Command (m for help): w
# format
[root@VM_0_89_centos ~]# mkfs.xfs /dev/vdb1
# get UUID and add to fstab
UUID="448467bd-f3fa-41cc-a5ad-ab316f7b62e2" /data1 xfs defaults 0 0
# mount and verify
[root@VM_0_89_centos ~]# mount -a
[root@VM_0_89_centos ~]# df -h

When expanding an MBR disk, a snapshot must be taken first, the disk must be unmounted, and the partition table is edited (often with parted or fdisk ) before resizing the filesystem.

4. GPT Disk Partition

Used for disks > 2 TB. The steps are similar to MBR but use parted to create a GPT label and partitions.

# create GPT label
[root@VM_0_89_centos ~]# parted /dev/vdb mklabel gpt
# create a partition covering the whole disk
[root@VM_0_89_centos ~]# parted /dev/vdb mkpart primary 2048s 100%
# format
[root@VM_0_89_centos ~]# mkfs.xfs /dev/vdb1
# add to fstab and mount
UUID="aa6fc333-e702-4daa-ad0b-10efde57a7f0" /data xfs defaults 0 0
# mount and verify
[root@VM_0_89_centos ~]# mount -a
[root@VM_0_89_centos ~]# df -h

To expand a GPT partition, the disk must be unmounted, the existing partition deleted, a new larger partition created (keeping the same start sector), and the filesystem enlarged (e.g., xfs_growfs or resize2fs ).

5. Summary

Three CBS usage methods: bare device, MBR partition, GPT partition.

Bare device allows online expansion; MBR/GPT require offline operations (unmount, repartition).

For cloud environments, bare‑device filesystems are recommended for simplicity and flexibility.

The article also provides author information and reference links to official Tencent Cloud documentation and video tutorials.