Differences: Disk vs Object Storage
A VDC offers two kinds of storage that solve different problems: disks (block storage) and object storage (S3). Knowing which is which helps you put data in the right place.
Disks (block storage)
A disk attaches to a virtual machine and behaves like a physical drive. The VM formats it, mounts it, and reads and writes files directly.
- Boot disk: holds the operating system. Every VM has one.
- Volume disk: optional extra storage for data.
- Each disk has a storage tier (Performance, Standard, or Archive) and can be resized upward.
- A disk belongs to one VM at a time. If you detach it or delete the VM while keeping it, it becomes an orphan disk that you can attach to another VM later.
Use disks for anything the operating system needs to treat as a local drive: the OS itself, databases, and application data.
Object storage (S3)
Object storage keeps files (objects) in buckets, accessed over the S3-compatible API rather than mounted on a VM. You read and write objects with S3 credentials from applications, scripts, or tools.
- Not attached to any VM. Any application with credentials can reach it.
- Designed for large or numerous files: backups, media, logs, static assets.
- Supports large uploads in parts, and object locking to keep files immutable for a set time.
Use object storage for data you access over the network rather than as a local drive: backups, file archives, and content served to many clients.
Choosing between them
| Need | Use |
|---|---|
| A drive for a VM's OS, database, or app files | Disk |
| Files accessed over an API by apps or scripts | Object storage |
| Resizable storage tied to one VM | Disk |
| Shared, large-scale file storage with immutability | Object storage |