What are the different storage tiers?

Data can migrate between the following Tiers on Stratus:
- Active Analysis
- Volume Storage
- Volume Storage
- Secure Archive
- dbGaP Cache (s3cache)
- Persistent Secure Storage (s3secure)
- Sanitized Data (i.e., non-protected and non-governed)
- Tier II (tier2)
- Archive Tape Storage*
(*) Availability TBD