GAD is used by storage arrays to replicate the contents of the array storage pools across two geographically separate sites. A storage pool is a logical container for a collection of four or more VSP One File system drives (SDs). Storage pools can be tiered (for older systems that contain a mix of flash drives and hard disk drives) or untiered
An untiered storage pool uses just one underlying pool from each block array. A tiered storage pool uses two or more underlying pools for each array. These can be a combination of high performance drives, such as Non-Volatile Memory Express (NVMe), with lower performance drives such as Serial Attached SCSI (SAS) or Near Line SAS (NL SAS). New deployments of Disaster Recovery Solution version 10.0 will use all VSP One Block all-flash systems. Therefore, tiering does not apply.
- Tier 0 is used for metadata. The best-performing storage should be designated as Tier 0.
- Tier 1 is used for user data.