PowerScale OneFS 9.2.1.0 CLI Administration Guide

View compression statistics

You can view reports about data compression that include current and historic compression ratios, as well as logical and physical data block totals.

1. To view a report that contains recent writes and total cluster data reduction, run the following command:
   isi statistics data-reduction
   The system displays output similar to the following example:

                 Recent Writes Cluster Data Reduction
                              (5 mins)
   --------------------- ------------- ----------------------
   Logical data                  1.07M                 49.57M
   Zero-removal saved                0                      -
   Deduplication saved               0                      0
   Compression saved                 0                      0
   Preprotected physical         1.07M                 49.57M
   Protection overhead           2.14M                 99.14M
   Protected physical            3.21M                160.61M
   
   Zero removal ratio         1.00 : 1                      -
   Deduplication ratio        1.00 : 1               1.00 : 1
   Compression ratio          1.00 : 1               1.00 : 1
   Data reduction ratio       1.00 : 1               1.00 : 1
   Efficiency ratio           0.33 : 1               0.31 : 1
   --------------------- ------------- ----------------------
   

   The Recent Writes column displays statistics for the previous five minutes. The Cluster Data Reduction column displays statistics for overall data efficiency across the entire cluster.
2. To view a report that contains statistics about compression ratios from the last five minutes, the percent of data that is not compressible, the total logical and physical data blocks that were processed, and writes where compression was not attempted, run the following command:
   isi compression stats view
   The system displays output similar to the following example:

    stats for 300 seconds at: 2021-02-25 19:20:36 (1614280836)
       compression ratio for compressed writes:  0.00 : 1
       compression ratio for all writes:  1.00 : 1
       incompressible data percent:  0.00%
       total logical blocks: 135
       total physical blocks: 135
       writes for which compression was not attempted: 100.00%

   • If the incompressible data percentage is high, the data being written to the cluster might be a type that has already been compressed.
   • If the number of writes for which compression was not attempted is high, you might be working with a cluster with multiple node types. If so, OneFS might be directing writes to a node pool that does not support data compression.
3. To view a report that contains the statistics that the isi compression stats view command provides, but also shows statistics from previous five minute intervals, run the following command:
   isi compression stats list
   The system displays output similar to the following example: