Introduction to
cloud services
This topic
provides a brief introduction to the cloud services available in IBM Spectrum Scale™.
Cloud services have the following two components:- Transparent cloud tiering
- Cloud data sharing
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.
Cloud 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.
This is useful when data needs to be distributed across multiple
domains or when large amounts of data needs to be transferred.
Figure 1 illustrates these features.
Transparent cloud tiering and Cloud data sharing features
- Supported
Transparent cloud tiering use cases
- 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.
- Transparent 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.
- For applications requiring tiering of data that scales beyond a
few billion files, you can configure up to four cloud services node classes as needed.
- Supported Cloud data sharing use cases
- 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.
cloud service 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 mailto:scale@us.ibm.com) to review your
use case of the Transparent cloud tiering feature and to obtain the
instructions to enable the feature in your environment.