Capacity saving effects for DP-VOLs and pools
You can use HDvM - SN or CCI to check the capacity saving effects for DP-VOLs, but you can only use HDvM - SN to check the capacity saving effects for each pool.
Certain types of DP-VOLs have high capacity saving values. These types of DP-VOLs should not be used as the basis of comparison with other DP-VOLs. The following conditions can cause abnormally high capacity saving values on DP-VOLs:
- DP-VOLs with large amounts of duplicated data have high capacity saving values due to the deduplication function.
- DP-VOLs that are replication targets of host-based or storage system-based replication usually have higher capacity saving values than DP-VOLs that are not replication targets.
The following figure illustrates the capacity saving effect for pools and DP-VOLs. Items with an asterisk (*) in the figure are displayed using CCI.
The following table lists the CCI commands that show the capacity saving effect for each pool.
| CCI command | Item in the figure | |
| Command name | Output of command | |
| raidcom get pool -key total_saving | SE_SAVING(BLK) | Saving under Saving effect |
| SES(%) | Saving ratio under Saving effect | |
| DATAVOL_USED(BLK) | Data volumes used capacity | |
| raidcom get pool -key software_saving | PLS(%) | Saving ratio under Software saving |
| PL_SAVING(BLK) | Saving under Software saving | |
| CMP(BLK) | Compression under Software saving | |
| DDP(BLK) | Dedup under Software saving | |
| RECLAIM(BLK) | Reclaim under Software saving | |
| SYSTEM(BLK) | System data under Software saving | |
| PL_PRE_USED(BLK) | Capacity before software saving | |
| PRE_CMP_USED(BLK) | Capacity before compression | |
| PRE_DDP_USED(BLK) | Capacity before deduplication | |
| raidcom get pool -key fmc | FMC_LOG_USED(BLK) | FMD logical used capacity |
| FMC_ACT_USED(BLK) | FMD used capacity | |
| FMC_PLV_USED(BLK) | FMD pool volumes used capacity | |
The following table lists the CCI commands that show the capacity saving effect for DP-VOLs.
| CCI command | Item in the figure | |
| Command name | Output of command | |
| raidcom get ldev | Used_Block(BLK) | Data volume used capacity |
| raidcom get ldev -key software_saving | TLS_R | Saving ratio of Software saving |
| TOTAL_SAVING(BLK) | Saving of Software saving | |
| CMP(BLK) | Compression of Software saving | |
| DDP(BLK) | Deduplication of Software saving | |
| RECLAIM(BLK) | Zero page reclaim of Software saving | |
| SYSTEM(BLK) | System data of Software saving | |
| PRE_USED(BLK) | Capacity which software saving does not affect | |
| POOL_USED(BLK) | Pool used capacity | |