Introduction to Start of changecloud servicesEnd of change

Start of changeThis topic provides a brief introduction to the cloud services available in IBM Spectrum Scale™End of change.

Start of changeCloud services have the following two components:
  • Transparent cloud tiering
  • Cloud data sharing
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Transparent cloud tiering is a feature of IBM Spectrum Scale that provides a native cloud storage tier. It allows data center administrators to free up on-premise storage capacity, by moving out cooler data to the cloud storage, thereby reducing capital and operational expenditures. The Transparent cloud tiering feature leverages the existing ILM policy query language semantics available in IBM Spectrum Scale, and administrators can define policies to tier data to cloud storage. On an IBM Spectrum Scale cluster with multiple storage tiers configured, this external cloud storage can be used as the cooler storage tier to store infrequently accessed data from a cool storage pool. For performance reasons, it is recommended not to move any active or hot data to this external storage pool, as it drives excessive data traffic on the Transparent cloud tiering which in turn can cause delays, leading to problems like application timeouts.

Start of changeCloud data sharing is an IBM Spectrum Scale cloud service that allows a way to set up sharing between IBM Spectrum Scale and various types of object storage, including IBM® Softlayer and IBM Cloud Object Storage. Furthermore, for export of data to object storage the service can be invoked from an ILM policy to allow for periodic sharing of data based on when the policy is run. For import, a list of files is specified for direct movement of data.End of change

Start of changeThis is useful when data needs to be distributed across multiple domains or when large amounts of data needs to be transferred. End of change

Figure 1 illustrates these features.

Figure 1. Start of changeTransparent cloud tiering and Cloud data sharing featuresEnd of change
Transparent cloud feature available with IBM Spectrum Scale Advanced Edition
Start of changeSupported Transparent cloud tiering use casesEnd of change
Tiering of file data from IBM Spectrum Scale file system to a cloud object storage, improving storage efficiency and cost effectiveness.
  • Data must be cool and not actively accessed by applications.
  • Specify selection of cool data by using ILM policies. You can use the policy to enable migration of files from a particular storage pool or fileset (existing ILM functions)
  • File stubs that are present in the IBM Spectrum Scale file system should not be removed.
  • When file stubs are accessed, files are transparently recalled (this feature can be used for occasional data access, not for high performance access as the latency can potentially cause application timeouts). It is recommended that customers must keep the transparent recall policy applied at all times on the file system that is managed by Transparent cloud tiering.
  • For high performance applications, use the policy to perform a bulk recall operation
  • For performance reasons, it is recommended that the average file size to be migrated to the cloud tier should be greater than 1 MB. Migration is supported for file size less than 1 MB, but performance will be slower due to overheads associated with small files.
  • For Transparent cloud tiering, data on the cloud object storage is opaque and cannot be accessed directly by applications. All I/O operations must happen through IBM Spectrum Scale system.
  • Start of changeTransparent cloud tiering works with IBM Spectrum Scale on multi-site stretch clusters to allow for continuance of access to cloud storage data even in the event of failure of an entire site.End of change
  • Start of changeFor applications requiring tiering of data that scales beyond a few billion files, you can configure up to four cloud services node classes as needed.End of change
Start of changeSupported Cloud data sharing use casesEnd of change
Sharing of data between IBM Spectrum Scale file system and cloud object storage provides an efficient way to move and distribute data between the two storage types
Unsupported use cases
Transparent cloud tiering does not support the following use cases:
  • Using Transparent cloud tiering to migrate/recall hot (active) data
  • Using Transparent cloud tiering as a backup mechanism
  • Using Transparent cloud tiering in disaster recovery scenarios.
Note: To enable Start of changecloud serviceEnd of change nodes, you must first enable the Transparent cloud tiering feature. This feature provides a new level of storage tiering capability to IBM Spectrum Scale customers. Please contact your IBM Client Technical Specialist (or send an email to to review your use case of the Transparent cloud tiering feature and to obtain the instructions to enable the feature in your environment.