HCP System Management Help


Ingest tier data protection level

The service plan for a given namespace defines one or more storage tiers for that namespace and specifies the data protection level (DPL) and the primary running storage metadata protection level (MPL) for each storage tier. The DPL for a given storage tier is the number of copies of the object data that HCP must maintain for each object that’s stored on that tier. The primary running storage MPL for a given storage tier is the number of copies of the object metadata that HCP must maintain on primary running storage for each object that’s stored on the tier.

Note: For any given storage tier, the primary running storage MPL must be equal to or greater than the DPL.

Every service plan initially defines primary running storage as the initial storage tier, called the ingest tier, and specifies a DPL setting and an MPL setting for that tier. If the HCP system is using economy storage, you can define HCP S Series as a service plan ingest tier to be used as an alternative to primary running storage. If an HCP S Series Pool, or pools, is selected as the ingest tier, DPL copies of objects are written directly to economy storage. Metadata DPL copies remains on primary running storage.

For each object in a given namespace, the ingest tier DPL is the number of copies of the object data that HCP must maintain on the ingest tier, from the time when the object is first stored until the time when the object data is moved to other storage devices (if multiple storage devices are defined for the namespace). The ingest tier MPL is the number of copies of the object metadata that HCP must maintain on primary running storage for as long as the object exists in the repository.

In the default namespace, each directory also has an ingest tier DPL setting. This setting is the same as the ingest tier DPL setting that’s specified in the service plan that’s assigned to the default namespace.

For both objects and directories, the ingest tier DPL setting is stored as metadata. Users and applications can see, but not modify, this metadata. For information on viewing ingest tier DPL settings, see Using a Namespace or Using the Default Namespace.

Note: When the ingest tier DPL of a namespace changes, for each object in that namespace that’s stored on the ingest tier, HCP creates or deletes copies of the object data, as needed to satisfy the new ingest tier DPL. This can take some time, during which some objects have the old required number of copies and some have the new. When viewing object metadata, however, users and applications always see the intended number of copies (that is, the ingest tier DPL specified in the service plan for the namespace).

Default ingest tier DPL setting

Each HCP system has a default service plan that’s automatically created and configured during the HCP software installation. The default service plan is applied to each tenant and namespace for which another service plan is not explicitly selected.

For any given HCP system, the ingest tier DPL setting that’s initially configured for the default service plan is used as the default ingest tier DPL setting for each new service plan that’s created on the HCP system. When you create a new service plan, you can choose to use the default ingest tier DPL setting or select a different setting. You can also modify any service plan, including the default service plan, to change the ingest tier DPL setting. However, changing the ingest tier DPL setting used for the default service plan does not change the default ingest tier DPL setting that’s used for new service plans.

Typically, the default ingest tier DPL setting used for service plans created on an HCP system is the optimal setting for the type of physical storage that the HCP system uses. For RAIN and VM systems, the default ingest tier DPL is two. For SAIN systems, the SAN arrays provide a high level of data protection, so the default ingest tier DPL setting is one.

The default ingest tier DPL setting used for all service plans that are created on an HCP system is the optimal setting for the type of storage used by that system. However, the optimal ingest tier DPL setting that’s configured for the service plan that’s assigned to a specific tenant or namespace is subject to considerations such as whether the tenant or namespace is being replicated and whether the HCP system owner or the tenant administrator has any particular data protection needs.

On HCP RAIN systems, by default, service plans can be configured to set the ingest tier DPL to two, three, or four. To enable HCP RAIN system administrators to configure service plans to set the ingest tier DPL to one, contact your authorized HCP service provider.

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