Each namespace has a service plan that defines both a storage tiering strategy and a data protection strategy for the objects in that namespace. At any given point in the lifecycle of an object, its storage tiering strategy specifies the types of storage on which copies of that object must be stored, and its data protection strategy specifies the number of object copies that must be stored on each type of storage.
The Storage Tiering service performs these functions according to rules specified in service plans:
•Moving copies of the objects in a given namespace among all of the storage tiers that are defined for that namespace by its service plan
•Creating and deleting copies of objects in a given namespace on each storage tier that is defined for that namespace to ensure that each tier always contains the correct number of copies of each object
•Changing objects stored on primary running storage to be metadata-only or restoring data to metadata-only objects
For the purpose of storage tiering, HCP treats these as individual objects:
•Parts of multipart objects. These parts are tiered based on the time of completion of the multipart upload that created the object.
•Chunks for erasure-coded objects. These chunks are tiered based on the object ingest time.
•Chunks for erasure-coded parts of multipart objects. These chunks are tiered based on the time of completion of the multipart upload that created the object.
The Storage Tiering service does not tier parts of in-progress multipart uploads.
The Storage Tiering service tiers full copies of the data for objects and parts that are subject to erasure coding if the target storage tier is primary running storage, S Series storage, or primary spindown storage. The service does not tier full copies of the data for objects and parts that are subject to erasure coding if the target storage tier is extended storage.
The Storage Tiering service can move objects and parts that are subject to erasure coding to a metadata-only storage tier before they are due to be reduced to chunks, provided that a full copy of the object or part data exists on at least one other system. While on the metadata-only tier, the object or part has metadata but no data.
If an object or part on a metadata-only storage tier is due to be reduced to a chunk, the Geo-distributed Erasure-Coding service gets the applicable chunk from another system. That service then removes the object or part from the metadata-only tier and stores the chunk for the object or part on the previous tier, as specified by the applicable service plan.
The Storage Tiering service does not move chunks for erasure-coded objects and parts to metadata-only storage tiers.
The Storage Tiering service runs according to the active service schedule.
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Important: HCP S Series Nodes run the risk of reaching maximum storage capacity. Objects do not tier to S Series Nodes that are full. |
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