How to interpret storage efficiency ratios in OnCommand System Manager
Applies to
OnCommand System Manager 9.0 or later
Description
- This article describes the procedure to interpret the storage efficiency ratios displayed in the OnCommand System Manager for ONTAP 9.0.
- Additionally, this can be used as a troubleshooting guide for the same.
- With significant improvements made in ONTAP 9.0 with respect to inline dedupe and inline compression, and new object compaction technologies, OnCommand System Manager represents the savings achieved through these technologies in terms of ratios.
- These ratios are visible in the dashboard for clusters with AFFp nodes only.
Terminology
- Logical Space Used:
- This is the sum of the used logical capacity represented by all files and LUNs attached to the storage system.
- For example, if you write total data of 10 GB to two different files, and if inline data compaction, data compression, and deduplication save space by 1 GB, the total logical space used are still 10 GB.
- Physical Space Used:
- This is the sum of the used physical capacity represented by all files and LUNs attached to the storage system.
- For example, if you write total data of 10 GB to two different files, and if inline data compaction, data compression, and deduplication reduce the total physical capacity to 1 GB, then the total physical space used is 1 GB.
- Savings from Storage Efficiency:
- This is the ratio of the total logical space that is used by the active file systems, snapshot copies, and FlexClone volumes to the total physical space that is used to store this data.
- Volume data reduction:
- This is the ratio of space savings due to data compression and deduplication.
- Aggregate data reduction:
- This is the ratio of space savings due to inline adaptive data compaction.
- FlexClone volumes and Snapshot copies:
- This is the ratio of logical data used by FlexClone volumes and Volume Snapshot copies to the number of physical blocks needed to store the data.