What cloud tiers and tiering policies are

Cloud tiers provide storage for infrequently accessed data. You can attach an all-flash (all-SSD) aggregate to a cloud tier to store infrequently used data. You can use tiering policies to decide whether data should be moved to a cloud tier.

You can set one of the following tiering policies on a volume:

Moves the Snapshot copies of only those volumes that are currently not being referenced by the active file system. Snapshot-only policy is the default tiering policy.
Moves the inactive (cold) data and the Snapshot copies from the active file system to the cloud tier.
Backup (for System Manager 9.5)
Moves the newly transferred data of a data protection (DP) volume to the cloud tier.
All (starting with System Manager 9.6)
Moves all data to the cloud tier.
Prevents the data on the volume from being moved to a cloud tier.