How to Resize a Partition in Linux Without Data Loss

Warning: Changing partitions is risky. Take a full backup or a snapshot of the server first. A mistake can destroy the data.

Understand your disk

A disk is split into partitions. Each partition has a file system (ext4, xfs and others). To make more room you grow the partition first, then grow the file system inside it.

Check the current partitions

lsblk

sudo fdisk -l

Check the free space

df -h

Method 1: growpart (easiest)

growpart extends a partition to use the free space after it. It is common on cloud VPS servers after you increase the disk size in the provider panel.

Step 1: Install growpart

Ubuntu and Debian:

sudo apt install cloud-guest-utils

CentOS, AlmaLinux and Rocky:

sudo yum install cloud-utils-growpart

Step 2: Grow the partition

Use the disk and the partition number (here the disk is /dev/sda and the partition is number 2):

sudo growpart /dev/sda 2

Step 3: Grow the file system

For ext4:

sudo resize2fs /dev/sda2

For XFS use the mount point instead:

sudo xfs_growfs /

Method 2: fdisk

With fdisk you delete the partition entry and create it again with the same start sector and a larger end. The data stays because only the partition table changes. The partition should not be mounted, or the file system must support online growing.

Step 1: Open fdisk on the disk

sudo fdisk /dev/sda

(Use the disk, not the partition.)

Step 2: Note the start sector, then delete the partition

Type p to print the table and write down the Start sector of the partition. Then type d and choose the partition number.

Step 3: Recreate the partition

Type n, choose the same partition number, enter the same start sector, and set a larger end (press Enter to use all the free space). When asked to remove the file system signature, answer No.

Step 4: Write the changes

Type w.

Step 5: Grow the file system

sudo resize2fs /dev/sda2

Method 3: parted

Step 1: Open parted

sudo parted /dev/sda

Step 2: View the layout

print

Step 3: Resize the partition

resizepart 2 100%

Type quit to leave.

Step 4: Grow the file system

sudo resize2fs /dev/sda2

Check the result

df -h
lsblk

Tips

Always back up first.
Do not shrink a partition before you shrink its file system, or you will lose data. Shrink the file system first, then the partition.
For LVM volumes, use lvextend -r -l +100%FREE /dev/vg/lv.

Quick recap

Grow the partition (growpart, fdisk or parted), then the file system (resize2fs or xfs_growfs).