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  • 1.  SpecV Compression Numbers

    Posted Mon November 29, 2021 03:04 PM
    Hello All,

    I try to understand what a SVC cluster (lssystem) is telling me.
    (No DRP)

    We see:
    compression_virtual_capacity value="189.00TB"
    compression_compressed_capacity" value="91.01TB"
    compression_uncompressed_capacity" value="153.02TB"
    tier1_flash_compressed_data_used" value="94.79TB

    where
    compression_compressed_capacity = Indicates the total used capacity for all compressed volume copies in non-data reduction pools.
    compression_uncompressed_capacity = Indicates the total uncompressed used capacity for all compressed volume copies in non-data reduction pools.
    (source lssystem -help)

    Is there any other explanation of these two statements and how I can match the numbers?

    Thank You

    ------------------------------
    T Masteen
    ------------------------------


  • 2.  RE: SpecV Compression Numbers

    Posted Tue November 30, 2021 08:03 PM
    Hello

    For contribute with more info:

    The following is from a V9000:

    lssystem -delim :
    total_mdisk_capacity:10.4TB
    space_in_mdisk_grps:10.4TB
    space_allocated_to_vdisks:2.26TB
    total_free_space:8.1TB
    total_vdiskcopy_capacity:8.18TB
    total_used_capacity:2.10TB
    total_overallocation:78
    total_vdisk_capacity:8.18TB
    total_allocated_extent_capacity:2.28TB
    tier:tier0_flash
    tier_capacity:10.40TB
    tier_free_capacity:8.12TB
    compression_active:yes
    compression_virtual_capacity:8.12TB ======> provisioned to hosts from Pool (vdisk)
    compression_compressed_capacity:2.05TB ======> after compression on mdisk
    compression_uncompressed_capacity:7.08TB======> before compression
    tier0_flash_compressed_data_used:2.22TB ===> mdisk

    My guess: ===>
    These parameters are for space saving calculation purpose.
    The differences between values: some are raw, other after format (mdisk), another virtual (pool) and the commented above is for compression purpose.

    More info for the analysis:
    The system has 30 volumes. For sample purpose, i posted 2 of 30:

    capacity     used_capacity  real_capacity    free_capacity  compressed_copy   uncompressed_used_capacity     overallocation   tier             tier_capacity  ratio
    200.00GB     58.03GB           62.03GB             4.00GB         yes                                136.26GB                                  322            tier0_flash      62.03GB      2.19
    500.00GB   130.52GB         140.52GB           10.00GB         yes                                459.11GB                                  355            tier0_flash    140.52GB       3.26

    So, not all data is compressible. Then inside of Compressed Volumes exists data compressed/uncompressed.
    Then the ratio is by volume (workload type) (it seems like media or email workload)

    Regards

    ------------------------------
    Humberto Sosa
    ------------------------------

    Original Message