Determining compression savings for volumes

Storage administrators can analyze an individual volume or all the volumes on a system for the potential capacity savings if compression is used.

The system supports several commands to analyze compression savings for volumes and display current status and results of previous analyses. These commands provide the functionality of Comprestimator Utility. The Comprestimator is an application that can be installed on hosts to estimate the capacity savings if compression was used in an environment. However, it requires access to hosts which a storage administrator might not have. Storage administrators can now use these CLI commands to analyze potential compression savings. If the compression savings are beneficial to your environment, you can use volume mirroring to convert volumes to compressed volumes.

To analyze a single volume for compression savings, complete these steps:
1. In the command-line interface, enter the following command:
```
analyzevdisk -vdisk_name | -vdisk_id 
```
  where -vdisk_name or -vdisk_name is either the name or identifier for the volume that you want to analyze for compression savings.
2. Analysis results can be displayed after the process completes by issuing the following command:
```
lsvdiskanalysis -vdisk_name | -vdisk_id 
```
  where -vdisk_name or -vdisk_id is either the name or identifier for the volume that you want to analyze for compression savings.
To analyze all the volumes that are currently on the system, complete these steps:
1. In the command-line interface, enter the following command:
```
analyzevdiskbysystem
```
  This command analyzes all the current volumes that are created on the system. Volumes that are created during or after the analysis are not included and can be analyzed individually with the analyzevdisk. Progress for analyzing of all the volumes on system depends on the number of volumes being analyzed and results can be expected at about a minute per volume. For example if a system has 50 volumes, compression savings analysis would take approximately 50 minutes.
2. To check the progress of the analysis, enter the following command:
```
lsvdiskanalysisprogress
```
  This command displays the total number of volumes on the system, the total number of volumes that are remaining to be analyzed, and the estimated time of completion.