What is Cloud Storage Gateway (CSG)?
Cloud Storage Gateway (CSG) is a gateway that you can deploy in your on-premises data center or on Alibaba Cloud. It uses Alibaba Cloud Object Storage Service (OSS) for backend storage and provides industry-standard file services (NFS and SMB) and block storage services (iSCSI) to on-premises and cloud applications. This lets you manage OSS resources in the same way that you manage on-premises folders and disks.
Prerequisites
Before you read this topic, you should understand the following concepts:
Product overview
Cloud Storage Gateway (CSG) provides file gateways and iSCSI gateways. You can select a gateway type based on your scenario:
File gateway
A file gateway maps the object structure of an OSS bucket to the directory and file structure of a Network-Attached Storage (NAS) file system. You can read and write objects in the specified OSS bucket using the standard NFS and SMB protocols. It also uses local storage to cache frequently accessed data. This ensures high-performance data access while you benefit from the massive storage capacity of OSS. File gateways are highly compatible with POSIX and third-party backup software. For scenarios that involve backing up and sharing small files for read and write access, you can use a standard or basic file gateway. If you have high performance requirements or multiple clients that need to access data at the same time, you can use an enhanced or performance-optimized file gateway.
iSCSI gateway
An iSCSI gateway creates storage volumes in OSS and provides access to them through the iSCSI protocol. On-premises applications can access these volumes as iSCSI targets. iSCSI gateways provide two modes: pass-through and cache.
Pass-through mode slices block volume data and synchronizes it to the cloud. This mode is suitable for customers who use high-speed connections, such as leased lines.
Cache mode uses the local cache disks of the gateway to accelerate read and write operations and asynchronously uploads cached data to the cloud. This mode is suitable for customers who require fast local access but have a slow connection to the cloud.
For more information, see Product Specifications.
Cloud Storage Gateway supports a wide range of application scenarios. For more information, see Scenarios.
Service architecture
CSG services on the cloud and gateway instances deployed in a customer's data center can form a storage gateway cluster. This cluster allows file data to move freely between the cloud and on-premises clusters. This facilitates collaborative data and service migration for typical scenarios, such as file backup, data distribution, and disaster recovery. You can also use the cluster to quickly publish data across multiple physical data centers.
As a lightweight storage gateway, it can be deployed in your on-premises data center or on Alibaba Cloud.
Usage
By default, a RAM user does not have any permissions. An administrator of an Alibaba Cloud account must grant permissions to the RAM user before the user can access resources that belong to the Alibaba Cloud account. For more information, see System policies for Cloud Storage Gateway.
You can create, use, and release a CSG instance in the following ways:
Manage a CSG instance in the console
CSG provides a web-based console. You can log on to the Cloud Storage Gateway console to manage your gateway instances.
Manage CSG using APIs
CSG provides APIs that you can use for custom development. For more information, see API reference.
Scenarios
File gateway
Building a file storage service with a massive file system when local storage is limited.
Storing data as objects in the cloud, but allowing applications to access the files using a file system without code modification.
Accessing shared folders across multiple data centers using a file storage service.
iSCSI gateway
Backing up data to the cloud using backup software that supports efficient data transfer over iSCSI.
Importing video stream data to storage volumes over iSCSI to store the data in the cloud.
Related Services and Documents
Elastic Compute Service: provides a simple, efficient, and elastic cloud computing service. For more information, see the ECS product page.
Object Storage Service (OSS): provides a massive, secure, cost-effective, and highly durable cloud storage service. For more information, see the Object Storage Service (OSS) product page.
Cloud Monitor: You can use Cloud Monitor to view monitoring data of your gateway resources. For more information, see the Cloud Monitor product page.
To mount an OSS bucket using CSG to manage OSS resources in the same way you manage on-premises folders and disks, see Mount an OSS bucket using Cloud Storage Gateway.