Network-Attached Volumes
Additional SSD storage volumes that can be attached to your VPS instances.
Overview
Volumes are network-attached block storage devices powered by Longhorn, providing persistent storage that can be attached and detached from VPS instances without requiring a restart. Volumes are independent from your VPS instance and persist even when the VPS is stopped or deleted.
Key Benefits
- Hotpluggable: Attach and detach volumes on running VMs without downtime
- Persistent: Data survives VPS restarts and can outlive the VPS instance
- Flexible Sizing: 10 GB to 500 GB, expandable at any time
- Replicated: Data is replicated across nodes for redundancy
Performance
Volumes use network-attached storage, which means data travels over the network between nodes. This results in different performance characteristics compared to the local NVMe root disk.
Benchmark Comparison
| Metric | Root Disk (Local NVMe) | Volume (Network-Attached) |
|---|---|---|
| Sequential Write | ~2.4 GB/s | ~50 MB/s |
| Sequential Read | ~10.2 GB/s | ~75 MB/s |
| Interface | virtio-blk | virtio-scsi |
| Storage Backend | OpenEBS LVM (local NVMe) | Longhorn (replicated) |
Why the Difference?
The root disk of your VPS uses local NVMe SSDs with direct access to the physical drive, delivering full NVMe speeds. Volumes use Longhorn network-attached storage, where data is replicated across multiple nodes over the network for redundancy. The current 1 Gbps network interconnect between nodes is the primary bottleneck (~125 MB/s theoretical max).
Upcoming Improvement
We are planning a 10 Gbps network upgrade that will significantly improve volume throughput, bringing speeds closer to 1 GB/s.
Recommended Use Cases
Volumes are ideal for:
- Bulk data storage (media files, archives, logs)
- Backup targets and data exports
- Application data that doesn't require high IOPS
- Extra storage when your root disk profile isn't enough
For latency-sensitive workloads (databases, caches, heavily accessed application files), keep your data on the local NVMe root disk.
Pricing
Volumes are billed at EUR 0.10/GB/month, calculated hourly.
| Size | Monthly Cost |
|---|---|
| 10 GB | EUR 1.00 |
| 50 GB | EUR 5.00 |
| 100 GB | EUR 10.00 |
| 500 GB | EUR 50.00 |
Getting Started
Creating a Volume
- Navigate to Storage > Volumes in the dashboard
- Click Create Volume
- Choose the volume size (10 - 500 GB)
- Enter a name for the volume
- Select the VPS instance to attach it to
- Click Create & Buy now
The volume will be created and automatically hot-plugged into your running VPS within a few seconds.
Using the Volume Inside Your VPS
Once attached, the volume appears as a new block device (typically /dev/sda or /dev/sdb). You need to format and mount it:
# Check available disks
lsblk
# Create a filesystem (first time only)
mkfs.ext4 /dev/sda
# Create a mount point and mount
mkdir -p /mnt/volume
mount /dev/sda /mnt/volume
# Verify
df -h /mnt/volume
To make the mount persist across reboots, add it to /etc/fstab:
echo '/dev/sda /mnt/volume ext4 defaults,nofail 0 2' >> /etc/fstab
Resizing a Volume
Volumes can only be expanded, not shrunk:
- Go to Storage > Volumes
- Click Resize on the volume
- Enter the new size
- The PVC expansion happens online, no restart required
After resizing, expand the filesystem inside the VPS:
resize2fs /dev/sda
Detaching a Volume
- Inside the VPS, unmount the volume first:Bash
umount /mnt/volume - Go to Storage > Volumes
- Click Detach on the volume
Warning: Detaching a volume permanently deletes the volume and all data on it.
Technical Details
- Storage Backend: Longhorn (replicated block storage)
- Storage Class:
longhorn-vps-volume - Volume Mode: Block
- Access Mode: ReadWriteOnce
- Bus: SCSI (for hotplug compatibility)
- Filesystem: User's choice (ext4 recommended)
- Replication: Configurable via Longhorn (default: 3 replicas)
Questions? Contact support at support@danubedata.ro