Block Storage Volumes - RamNode Cloud VPS Documentation

Block storage volumes provide additional persistent storage for your cloud instances. They can be attached, detached, and moved between instances as needed.

What is Block Storage?

Block storage volumes (also called Cinder volumes in OpenStack) are persistent storage devices that can be attached to cloud instances. Think of them like external hard drives that can be plugged into any instance.

Use Cases

Database Storage

Keep database files on separate volumes for easier backup and migration.

Additional Capacity

Add storage to instances without resizing or migrating.

Data Persistence

Keep data safe even if the instance is deleted.

Portable Storage

Move volumes between instances for flexibility.

Creating a Volume

Step 1: Access the Cloud Control Panel

Log into the Cloud Control Panel and navigate to Volumes → Volumes.

Step 2: Create New Volume

Click Create Volume and configure the following settings:

Name - Descriptive name for the volume
Description - Optional description
Size - Size in GB (minimum 1 GB)
Volume Type - Select storage type (SSD recommended)
Availability Zone - Must match your instance's zone

Click Create Volume to provision the storage.

Attaching a Volume

Step 1: Attach to Instance

Once created, attach the volume to an instance:

Select the volume from your volumes list
Click Manage Attachments
Select the instance to attach to
Click Attach Volume

The volume will appear as a new disk device on your instance (typically /dev/vdb, /dev/vdc, etc.).

Formatting and Mounting

Step 1: Check Device Name

After attaching, identify the device:

# List all block devices
lsblk

# You should see your new volume (e.g., vdb)

Step 2: Format the Volume

Warning

Formatting will erase all data on the volume. Only format new volumes or volumes you want to wipe clean.

Format with your preferred filesystem (first time only):

# Format with ext4 filesystem
mkfs.ext4 /dev/vdb

# Or with XFS
mkfs.xfs /dev/vdb

Step 3: Mount the Volume

Create a mount point and mount the volume:

# Create mount point
mkdir /mnt/data

# Mount the volume
mount /dev/vdb /mnt/data

# Verify it's mounted
df -h /mnt/data

Step 4: Make it Permanent

To automatically mount the volume on boot, add it to /etc/fstab:

# Get the UUID
blkid /dev/vdb

# Add to /etc/fstab (replace UUID with your actual UUID)
echo "UUID=your-uuid-here /mnt/data ext4 defaults,nofail 0 2" >> /etc/fstab

Detaching a Volume

Step 1: Safely Detach

To detach a volume from an instance:

First, unmount the volume:
```
umount /mnt/data
```
In the Cloud Control Panel, go to the volume
Click Manage Attachments
Click Detach Volume

Moving Volumes Between Instances

Volumes can be moved between instances while preserving all data:

Unmount the volume on the current instance
Detach from the current instance
Attach to the new instance
Mount on the new instance

This is useful for migrating databases or moving data between instances without any data transfer overhead.

Volume Snapshots

Create snapshots of volumes for backup:

Select the volume
Click Create Snapshot
Give it a descriptive name
Click Create Volume Snapshot

Snapshots can be used to create new volumes, providing an easy backup and cloning mechanism.

Pricing

Block storage is billed hourly based on the allocated size:

Charged per GB per month (prorated hourly)
Billing continues even if volume is not attached
Snapshots also incur storage charges
Delete unused volumes to avoid charges

Performance Tips

Right-size volumes

Over-provisioning wastes money

Consider instance storage

For temporary data, use instance disk instead

Regular snapshots

Create backups of important volumes

Limitations

Volumes must be in the same region as the instance
A volume can only be attached to one instance at a time
Volume size can be increased but not decreased
Maximum volume size varies by plan and region

Pro Tip

Use block storage for data you want to persist beyond the instance lifetime. For temporary or disposable data, use the instance's local storage to save costs.