> ## Documentation Index
> Fetch the complete documentation index at: https://docs.xloud.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Storage Types

> Understand block, object, and shared file storage in XSDS — capabilities, use cases, and how to choose the right interface for your workload.

## Overview

XSDS exposes three distinct storage interfaces from a single distributed platform.
Each interface suits a different application pattern — selecting the right type for
your workload is the first step to optimal performance and cost efficiency.

<Note>
  **Prerequisites**

  * An active Xloud account with project access
  * Familiarity with your application's I/O pattern (random vs sequential, latency vs throughput)
</Note>

***

## Storage Interface Comparison

| Interface               | Protocol           | Access Pattern                 | Typical Use Case                     |
| ----------------------- | ------------------ | ------------------------------ | ------------------------------------ |
| **Block Storage**       | RBD / iSCSI        | Random read/write, low latency | Instance boot disks, databases, OLTP |
| **Object Storage**      | S3-compatible HTTP | Large objects, high throughput | Backups, media files, data lakes     |
| **Shared File Storage** | NFS / SMB          | Concurrent multi-client        | Home directories, shared configs     |

***

## Block Storage

<Tabs>
  <Tab title="Overview" icon="hard-drive">
    Block storage volumes attach to Xloud Compute instances as persistent disks. Volumes
    exist independently of instance lifecycle — data survives instance deletion and can
    be re-attached to a different instance.

    **Capabilities:**

    | Capability    | Details                                                  |
    | ------------- | -------------------------------------------------------- |
    | Hot-attach    | Attach to running instances without rebooting            |
    | Online resize | Extend volume size without downtime (extend only)        |
    | Snapshots     | Point-in-time copies for recovery or cloning             |
    | Encryption    | At-rest encryption via the Xloud Key Management service  |
    | QoS           | IOPS and throughput limits configurable via volume types |

    <Tip>
      Select a volume type that matches your workload's I/O profile. NVMe-backed types
      suit latency-sensitive databases; HDD-backed types suit large sequential workloads
      like backups and archives.
    </Tip>
  </Tab>

  <Tab title="Best For" icon="circle-check">
    Block storage is ideal when your workload requires:

    * Exclusive read/write access from a single instance
    * Predictable low-latency I/O (sub-millisecond for NVMe-backed volumes)
    * POSIX-compliant file system on top of the volume (ext4, XFS, etc.)
    * Database workloads: PostgreSQL, MySQL, MongoDB, Redis

    See the [Xloud Block Storage guide](/services/storage/user-guide) for complete
    volume lifecycle management procedures.
  </Tab>
</Tabs>

***

## Object Storage

<Tabs>
  <Tab title="Overview" icon="box">
    Object storage provides an S3-compatible API for storing and retrieving unstructured
    data — images, backups, logs, media files, and application artifacts — at any scale.

    **Capabilities:**

    | Capability             | Details                                                              |
    | ---------------------- | -------------------------------------------------------------------- |
    | S3 API compatibility   | Works with standard S3 clients, SDKs, and tools                      |
    | Bucket ACLs            | Per-bucket and per-object access control                             |
    | Lifecycle policies     | Automate object expiration and tiering                               |
    | Object versioning      | Retain multiple versions of objects for accidental-delete protection |
    | Multi-part upload      | Efficient upload for large files (> 100 MB)                          |
    | Server-side encryption | Transparent encryption at write time                                 |
    | Static website hosting | Serve static content directly from buckets                           |

    <Note>
      Access credentials for object storage are separate from your Xloud Dashboard
      credentials. Generate S3-compatible access keys from the Dashboard under
      **Project → Object Store → Access Keys**.
    </Note>
  </Tab>

  <Tab title="Best For" icon="circle-check">
    Object storage is ideal when your workload requires:

    * Storing large volumes of unstructured data (images, videos, documents, logs)
    * Application integration via standard S3 SDK (boto3, AWS SDK, MinIO client)
    * Multi-region data distribution and static content delivery
    * Cost-efficient backup and archival with erasure-coded pools
  </Tab>
</Tabs>

***

## Shared File Storage

<Tabs>
  <Tab title="Overview" icon="folder-open">
    Shared file storage provides a POSIX-compliant distributed file system accessible
    from multiple instances simultaneously — suitable for home directories, shared
    configuration, and workloads that require concurrent read/write access.

    **Capabilities:**

    | Capability           | Details                                                     |
    | -------------------- | ----------------------------------------------------------- |
    | POSIX semantics      | Full file system compliance including permissions and links |
    | Multi-client access  | Concurrent read/write from many instances at once           |
    | NFS and SMB gateways | Compatible with Linux and Windows clients                   |
    | Per-directory quotas | Control storage consumption per share or directory          |
    | Directory snapshots  | Point-in-time recovery at the directory level               |

    <Warning>
      Shared file storage throughput is distributed across all connected clients. For
      high-IOPS workloads requiring exclusive access, use a dedicated block volume
      instead.
    </Warning>
  </Tab>

  <Tab title="Best For" icon="circle-check">
    Shared file storage is ideal when your workload requires:

    * Concurrent read/write access from multiple instances simultaneously
    * Legacy NFS-mounted application data directories
    * Shared configuration files across a cluster of application nodes
    * Collaborative workloads where multiple users write to the same directory tree
  </Tab>
</Tabs>

***

## Choosing the Right Type

<AccordionGroup>
  <Accordion title="My application is a relational database" icon="database">
    Use **Block Storage**. Databases require low-latency random I/O and exclusive
    access to their data files. Choose an NVMe or SSD-backed volume type for
    production OLTP databases.
  </Accordion>

  <Accordion title="I need to store uploaded user files or media" icon="image">
    Use **Object Storage**. Media files, documents, and user uploads benefit from
    the S3 API's simplicity, scalability, and built-in lifecycle management. Applications
    integrate via the S3 SDK — no mounting required.
  </Accordion>

  <Accordion title="Multiple instances need to read and write the same data" icon="users">
    Use **Shared File Storage**. If your application tier requires a common data
    directory accessible by all instances (e.g., a shared cache, log directory, or
    configuration tree), shared file storage provides concurrent access with POSIX
    semantics.
  </Accordion>

  <Accordion title="I need to store backups at low cost" icon="archive">
    Use **Object Storage** with an erasure-coded pool. Erasure coding reduces storage
    overhead to 1.33–1.5× compared to 3× for replicated storage, making it the most
    cost-efficient option for backup and archival workloads where access is infrequent.
  </Accordion>
</AccordionGroup>

***

## Next Steps

<CardGroup cols={2}>
  <Card title="Access Methods" href="/services/sds/user-guide/access-methods" color="#197560">
    Connect to each storage type — Dashboard, CLI, S3 API, and mount protocols
  </Card>

  <Card title="Data Protection" href="/services/sds/user-guide/data-protection" color="#197560">
    Configure replication and erasure coding for each storage type
  </Card>

  <Card title="Snapshots" href="/services/sds/user-guide/snapshots" color="#197560">
    Create and restore snapshots for block volumes and object buckets
  </Card>

  <Card title="Block Storage User Guide" href="/services/storage/user-guide" color="#197560">
    Full volume lifecycle management — create, attach, extend, and back up volumes
  </Card>
</CardGroup>