Cloud Storage Gateway (CSG) is a gateway service that can be deployed at your data center and in Alibaba Cloud. CSG uses Alibaba Cloud Object Storage Service (OSS) buckets as backend storage devices, and provides on-premises and in-cloud applications with standard file services over the Network File System (NFS) and Server Message Block (SMB) protocols and block storage services over the Internet Small Computer Systems Interface (iSCSI) protocol.

CSG supports two types of gateways:

  • File gateways

    File gateways use OSS buckets as backend storage devices, and map the object directory structure of OSS buckets to the file system of Network Attached Storage (NAS). You can read and write all objects in a specified OSS bucket over the standard NFS and SMB protocols. CSG also uses local storage to cache hot data, and provides high-performance data access in addition to large space of OSS buckets. File gateways are compatible with the Portable Operating System Interface (POSIX) and third-party backup software. We recommend that you use standard or basic types of file gateways to back up, share, read from, and write to small files. If you require excellent performance or use multiple clients to access data, we recommend that you use enhanced and advanced types of file gateways.

  • Block gateways

    Block gateways provide storage volumes in OSS, and support connections over the Internet Small Computer Systems Interface (iSCSI) protocol. Local applications access these volumes as iSCSI targets. Block gateways run in two modes: write-through and cache. In write-through mode, the data in iSCSI volumes is sliced and synchronized to the cloud. This mode is applicable when you use high-speed links such as leased lines. In cache mode, you can create local cache disks to accelerate read and write operations, and transfer data to the cloud in an asynchronous manner. This mode is applicable when you require efficient access to locally cached data but common performance of uploading data to OSS.

Architecture

You can use in-cloud gateways and local gateway instances to build a storage gateway cluster. In this way, you can share data between clusters deployed in Alibaba Cloud and on the premises. This helps you to migrate business data and services in various scenarios, such as file backup, data distribution, and disaster recovery. You can also use the clusters to efficiently distribute data to multiple server rooms.

As a lightweight storage gateway, you can deploy CSG both at your data center and in Alibaba Cloud.

Architecture

Scenarios

  • File gateways
    • Build a file storage service for a large file system when local storage is limited.
    • Store data as objects in the cloud, and allow applications to access the data in a file system without modifying code.
    • Access shares in a file storage service among multiple data centers.
  • Block gateways
    • Create data backups in the cloud by using backup software that supports efficient transmission over iSCSI.
    • Import video streams to storage volumes through iSCSI-based connections to store data in the cloud.