Cluster and filesystem capacity counter definitions

Understand the key capacity counters for effective storage management, including space utilization, availability, and data reduction across SSDs and object storage.

Cluster capacity counter definitions

SSD capacity counters:
- USED SSD: Total SSD space currently in use, including both data and metadata.
- USED SSD (DATA): Space on SSDs occupied by actual file data.
- USED SSD (META): Space on SSDs used for storing filesystem metadata.
- FREE SSD: Available unused space on SSDs.
- AVAILABLE SSD (META): Remaining SSD space available for storing filesystem metadata.
- AVAILABLE SSD: Total SSD space provisioned to the filesystem by the user.
Total capacity counters:
- USED TOTAL: Total space used across both SSD and object store for filesystem data and metadata.
- USED TOTAL (DATA): Total space consumed by file data across the entire filesystem.
- FREE TOTAL: Remaining space available in the filesystem for storing data and metadata.
- AVAILABLE TOTAL: Total allocated space across both SSD and object store tiers.
Data reduction counters:
- DATA REDUCTION RATIO (DRR): Data reduction efficiency, calculated as: USED SSD (DATA) / REDUCED SIZE OF DATA.
- USED SSD PENDING DATA REDUCTION: Amount of data written to SSD that is awaiting data reduction processing.
- REDUCED SIZE OF PROCESSED DATA: Total SSD space occupied post data reduction processing.
- REDUCED SIZE OF DATA: Total SSD space consumed by the filesystem after all data reduction operations are complete.
- PROCESSED DATA REDUCTION RATIO: Storage efficiency that shows actual space savings achieved through data reduction and deduplication. Calculated as: (USED SSD (DATA) - USED SSD PENDING DATA REDUCTION) / REDUCED SIZE OF PROCESSED DATA
Other counters:
- THIN PROVISIONED MINIMUM SSD: Minimum guaranteed space.
- THIN PROVISIONED MAXIMUM SSD: Maximum limit of space that can be dynamically allocated.
- USED SSD (WRITECACHE): SSD space consumed by modified data, possibly pending tiering to object store.
- USED SSD (READCACHE): Total SSD space used for caching data that also exists in the object store, based on filesystem group tiering policies.

Example scenarios

Thin provisioned filesystem (no data reduction)

FILESYSTEM NAME: fs_example1
THIN PROVISIONED: true
THIN PROVISIONED MINIMUM SSD: 100 TB
THIN PROVISIONED MAXIMUM SSD: 500 TB
USED SSD: 150 TB
USED SSD (DATA): 145 TB
USED SSD (META): 5 TB
FREE SSD: 350 TB

Filesystem with active data reduction

FILESYSTEM NAME: fs_example2
DATA REDUCTION: Enabled
USED SSD: 200 TB
USED SSD (DATA): 150 TB
PENDING DATA REDUCTION: 50 TB
REDUCED SIZE OF PROCESSED DATA: 40 TB
DATA REDUCTION FACTOR: 3.75