Increasing the size of an additional disk – Support Guides

Learn how to increase the size of an additional disk and extend the main partition accordingly.

If you have reached the maximum capacity of your additional disk, you can add more storage by increasing its size.

Requirements

A Public Cloud instance in your Public Cloud project
An additional disk created in your project
Administrative (root) access to your instance via SSH (Linux) or RDP (Windows)

OVHcloud Control Panel Access

Direct link: Public Cloud Projects
Navigation path: Public Cloud > Select your project

Instructions

The following steps presume that you have configured an additional disk according to our guide.

Monitoring disk usage before resizing

NOTE: We recommend that you always maintain 20% free space on your storage volumes. This ensures optimum performance and avoids the risk of system degradation or failure when the volume reaches its maximum capacity.

To ensure that you resize your disk at the right moment, it is essential to monitor disk usage regularly. Below are quick tutorials for both Windows and Linux to help you track disk space and anticipate when an upgrade is needed.

Using Command Prompt

Open Command Prompt (Win + R → cmd → Enter).

Run the following command:

wmic logicaldisk get name, size, freespace

This will display the free space and total size of each disk.

Using PowerShell

Open PowerShell as Administrator.

Run the following command:

Get-PSDrive | Where-Object {$_.Free -ne $null} | Select-Object Name, Used, Free

This will show the used and available disk space.

Using the 'df' command

To check overall disk usage, run:

df -h

This will display disk usage in a human-readable format.

Using the 'lsblk' command

To view disk partitions and their sizes:

lsblk

Modifying the size of the disk

Click on Block Storage in the left-hand menu.

If the volume is attached to a Windows instance, click on the more options ... button in the row of the volume and select Detach from instance.

Click on ... in the row of the volume and select Edit.

In the next screen, increase Volume capacity and click Modify the volume.

Extending the partition

Before proceeding, reattach the volume to the instance. Click the more options ... button to the right of the volume and select Attach to instance.

Establish a remote desktop (RDP) connection to your Windows instance.

Once logged in, right-click on the Start Menu button and open Disk Management.

The extended disk now displays the additional capacity as unallocated space.

Right-click on the volume and select Extend Volume from the context menu.

In the "Extend Volume Wizard", click on Next to proceed.

You can modify the disk space in this step if you want to add less than the entire amount to the partition. Click on Next.

Click on Finish to complete the process.

The resized volume now includes the additional disk space.

Once this is completed, detach and reattach the volume to the instance to ensure the updated QoS settings (IOPS and bandwidth) are properly applied.

Establish an SSH connection to your instance in order to adjust the partition to the resized disk.

Unmount the disk first by using this command:

sudo umount /mnt/disk

Recreate the partition:

sudo fdisk /dev/sdb

Welcome to fdisk (util-linux 2.25.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command

Command (m for help): d

Selected partition 1
Partition 1 has been deleted.

Command (m for help): n

Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (1-4, default 1):
First sector (2048-146800639, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-146800639, default 146800639):

Created a new partition 1 of type 'Linux' and of size 70 GiB.

Command (m for help): w

The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

Verify and check the partition:

sudo e2fsck -f /dev/sdb1

e2fsck 1.42.12 (29-Aug-2014)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/sdb: 12/3276800 files (0.0% non-contiguous), 251700/13107200 blocks

sudo resize2fs /dev/sdb1

resize2fs 1.42.12 (29-Aug-2014)
Resizing the filesystem on /dev/sdb to 18350080 (4k) blocks.
The filesystem on /dev/sdb is now 18350080 (4k) blocks long.

Finally, re-mount and check the disk:

sudo mount /dev/sdb1 /mnt/disk/

df -h
Filesystem   Size   Used   Avail   Use%   Mounted on
/dev/vda1    9.8G   840M    8.6G     9%   /
udev          10M      0     10M     0%   /dev
tmpfs        393M   5.2M    388M     2%   /run
tmpfs        982M      0    982M     0%   /dev/shm
tmpfs        5.0M      0    5.0M     0%   /run/lock
tmpfs        982M      0    982M     0%   /sys/fs/cgroup
/dev/sdb1     69G    52M     66G     1%   /mnt/disk