Block storage volumes explained: when and how to use them

Your VPS is humming along, then the disk starts filling — a growing database, piles of user uploads, backups, media files. The instinct is to resize the whole server, but that's often the wrong tool. Block storage lets you attach extra disk to an existing VPS independently, so you add exactly the space you need without touching your compute or rebuilding anything. Here's what block storage is, when to reach for it, and how to attach and mount a volume on Linux.

What block storage actually is

A block-storage volume is a virtual disk you can attach to a server, separate from the server's built-in OS disk. To the operating system it looks and behaves like a physical drive: you format it, mount it, and read and write files to it as usual. But it's decoupled from the VPS — you can detach it, keep it, and reattach it elsewhere.

On Nxeon, volumes are NVMe-backed, so the extra capacity is fast, not a slow bulk tier. You get performance and room at the same time, billed simply at a flat per-GB monthly rate for what you provision.

Block storage vs resizing the server

Both give you more disk, but they solve different problems:

• Resizing the VPS grows the base plan — usually vCPU, RAM *and* disk together. Use it when you need more *compute*, not just space.
• A block-storage volume adds *only* storage, independently, and can be attached, detached and moved. Use it when your CPU and RAM are fine but you're running out of room.

If your server is fast enough but the disk is filling, a volume is the cheaper, cleaner answer than paying for a bigger plan you don't otherwise need.

When a volume is the right choice

• Databases that keep growing. Put the data directory on a volume so it can expand without resizing the whole box.
• User uploads and media. Images, video and documents pile up; a volume keeps them off the OS disk.
• Backups and archives. Store local backups on separate storage so a full OS disk never takes down the server.
• Data you want to outlive the server. Because a volume survives detachment, you can destroy and rebuild the VPS while keeping the data intact on the volume.
• Portable datasets. Move a volume between servers to shift a large dataset without copying it over the network.

A key benefit: your data survives detach

This is the feature people underrate. A block-storage volume is independent of the server's lifecycle. Rebuild the VPS, reinstall the OS, or migrate to a new server, and the volume — with all its data — is still there to reattach. Your important data lives on storage that isn't tied to any one server instance, and the OS disk stays protected because your growing data isn't crammed onto it.

How to attach and mount a volume

The workflow on Nxeon takes three steps: create, attach, mount.

1. Create the volume in your dashboard, choosing the size you need (you're billed per GB for what you provision).

2. Attach it to your VPS. It appears in the server as a new block device, typically something like /dev/sdb or /dev/vdb. Confirm which:

lsblk

Look for the new, unmounted device at the size you created.

3. Format it (first time only). A brand-new volume has no filesystem. Create one — ext4 is a safe default:

sudo mkfs.ext4 /dev/sdb

Only do this on a *new* volume — formatting erases data, so never run it on a volume that already holds files.

4. Mount it. Make a mount point and mount the volume there:

sudo mkdir -p /mnt/data
sudo mount /dev/sdb /mnt/data

Your extra space is now available at /mnt/data.

5. Mount it automatically on boot. So it comes back after a reboot, add it to /etc/fstab. Use the volume's UUID rather than the device name, which can change:

sudo blkid /dev/sdb
# then add a line to /etc/fstab using the UUID, e.g.:
# UUID=xxxx-xxxx  /mnt/data  ext4  defaults,nofail  0  2

The nofail option means the server still boots even if the volume is ever detached — a sensible safety net.

Putting a service's data on the volume

Once mounted, point your application at it. For a database, that means moving the data directory to the volume and updating the config to use the new path; for uploads, storing them under the mount point. Stop the service, move the data, update the path, restart — and from then on your growing data lands on the volume, keeping the OS disk lean.

A few good practices

• Use nofail in fstab so a detached volume never blocks boot.
• Mount by UUID, not device name, to avoid surprises if device ordering changes.
• Don't reformat an existing volume — that erases it. Only mkfs a fresh one.
• Back up volume data too. A volume is durable storage, not a backup by itself; keep real backups of anything important.
• Right-size, then grow. Start with what you need and provision more capacity later rather than over-buying up front.

Add space the smart way

When your server's fast enough but the disk is tight, you don't need a bigger plan — you need more storage. Block-storage volumes give you NVMe-backed capacity you can attach, keep on detach and move between servers, at a flat $0.10 per GB / month on Nxeon. Read more and create your first volume at /block-storage, or explore VPS plans at /vps.