The total saving effect achieved by capacity saving, Dynamic Provisioning, and snapshot is displayed in management software. System data (metadata and garbage data for the capacity saving function, Thin Image Advanced metadata) is not included in the Total Efficiency Ratio. These examples show the relationship between the total efficiency and the efficiency achieved by each function.
- The Total Efficiency Ratio and associated efficiency values do not include the total capacity and used capacity of these volumes:
- Journal volumes
- Volumes with the data direct mapping attribute
- Command devices
- Deduplication system data volumes (fingerprint and data store)
- S-VOLs used in Thin Image Advanced
- Quorum disks
- Remote command devices
- When a pool is blocked, the values before the pool is blocked are displayed by management software, and the values are updated after the pool is restored.
- When any of these operations is performed, the Total Efficiency Ratio and associated values displayed by management software and CCI might be lower than the actual values:
- Creating LDEVs or increasing the LDEV capacity
- Initializing duplicated data
- Reclaiming zero data page
- Deleting or formatting LDEVs
- Creating snapshots in Thin Image Advanced
- Deleting S-VOLs used in Thin Image Advanced
- The Total Efficiency Ratio and associated efficiency values change according to configuration changes and the type of I/O load. The efficiency values are more accurate when I/O loads are not high. You might obtain lower values immediately after performing operations.
- If data is written across the DP-VOL, the Total Efficiency Ratio might become less than 1.
- It takes up to 90 minutes to calculate the Total Efficiency Ratio and associated efficiency values.
Example for deduplication and compression of the capacity saving function
These figures show the Total Efficiency Ratio and Software Saving Ratio achieved when deduplication and compression of the capacity saving function are used.
Total Efficiency Ratio for controller-based deduplication and compression on DRS-VOLs
Software Saving Ratio for controller-based deduplication and compression on DRS-VOLs
Software Saving Ratio for controller-based deduplication and compression by using dedupe and compression on DRD-VOLs
Efficiency values
The raidcom get system -key efficiency CCI command displays the efficiency values for the entire storage system, and the raidcom get pool -key efficiency CCI command displays the efficiency values for the specified pool:
- TOTAL_EFF_R
- TLS_R
- PLS_R
- PLS_CMP_R
- PLS_DDP_R
- PLS_RECLAIM_R
- SNAPSHOT_EFF_R
- PROVISIONING_EFF(%)
The following values are the maximums of each saving effect ratio that can be displayed in CCI:
- CCI: 92233720368547758.07 (a hundredth value of hexadecimal 0x7FFFFFFFFFFFFFFF)
If no data is stored in the pool as shown in the following example, the saving effect ratio displays the maximum available value. If data is stored, the saving effect ratio calculated from the amount of actual data reduction is displayed.
The following examples show the condition where the maximum values are displayed:
Example 1: Total Efficiency Ratio after the pool and DP-VOL creations but before data writing:
- CCI: 92233720368547758.07
Example 2: Snapshot Efficiency Ratio that applies when the pool includes Thin Image Advanced pairs in the PAIR status, or pairs with no differential data:
- CCI: 92233720368547758.07
The GET <base URL>/v1/objects/total-efficiencies/instance REST API request displays the efficiency values for the entire storage system, and the GET <base URL>/v1/objects/pools/<object ID>?detailInfoType=efficiency request displays the efficiency values for the specified pool:
- totalRatio
- compressionRatio
- dedupeAndCompression.totalRatio
- dedupeAndCompression.compressionRatio
- dedupeAndCompression.dedupeRatio
- dedupeAndCompression.reclaimRatio
- snapshotRatio
- provisioningRate