When you create an auto‑tiered LUN, you select the initial properties for QoS and Storage Class, and you provide the capacity requirements for the LUN. By default, the system has access to all of the available Storage Classes for data migration.
An auto‑tiered LUN is a LUN that uses the auto‑tier (QoS Plus) feature. This feature uses the configured Storage Class within the Storage Domain to optimally store the data and to make the best use of the available storage types and capacities. Even though the system sets the LUN initially to single tier, you can select the auto-tier option, if desired.
As data is stored and retrieved in the LUN, the Oracle FS System migrates that portion of the data to the appropriate Storage Classes. This process is called data migration. Data migration that results from the QoS Plus feature occurs when the system, after an analysis of the historical usage information for the block of data, determines that another Storage Class or RAID level can better service that block of data.
Auto‑tiered LUNs can access all of the configured Storage Classes in the Storage Domain. When you create an auto‑tiered LUN, you are presented with a graphical representation of the Storage Domain capacities and the storage allocation by Storage Class. The graphs provide an overview of the potential storage usage for the LUN so that you can plan your storage requirements appropriately.
Administrators can create Storage Domains in the system. When the system contains more than one Storage Domain, the Storage Domain field displays on the GUI screen. Otherwise this field is not present in the GUI and the system assigns the LUN to the default Storage Domain.
The Create LUN dialog contains three tabs for entering the QoS information and mapping the LUN to a host entry.
Enter the LUN volume name, and then select a Storage Profile that contains predefined QoS attributes. If necessary, choose the custom QoS attributes. The system contains two levels of QoS settings: Basic and Advanced.
The QoS settings that you enter for your LUN help the system determine the initial placement of the data. When enough statistics and usage history is collected about the data, the system determines whether to move some of the data to a different storage tier.
When you create an auto‑tiered LUN and request a non-zero amount of capacity to be allocated, the Oracle FS System takes a few minutes to reserve that capacity. Until the capacity allocation process completes, the system reports the allocated capacity as zero (0). After the allocation process completes, the system reports the amount of allocated capacity that you originally requested.
(Optional) The Mapping tab allows you to specify which SAN host entries can access the LUN.
Map the LUN to a SAN host entry using a specific LUN number.
Map all SAN host entries to access the LUN using the same LUN number. This method is not recommended.
(Optional) The Data Protection tab allows you to allocate the storage capacity for the Clone LUNs repository. You can apply unique QoS properties to the Clone LUN repository and assign the maximum storage capacity for the repository. You can also create a clone schedule to perform data protection at regular intervals.