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  • 1.  Flashsystem 7300 not show written capacity

    Posted 3 days ago

    Hello!

    Some luns show "Not enough data" in written capacity column:

    But this luns are not empty:

    What may be reason of this behavior?

    Thanks.



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    A. S.
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  • 2.  RE: Flashsystem 7300 not show written capacity

    Posted 3 days ago

    Hi,

    What does the current pool usage look like? is it DRP? Are the volumes being presented full or thin provisioned or compressed? I vaguely remember when we used thin and compressed on the same volume, the storage said it wasn't able to show the true used written capacity for the volume.

    It could also be the type of data being written to those specific vdisks, if the storage cannot read encrypted files being stored then it probably wouldn't be able to accurately report usage.

    Does command line show the same metrics?

    I assume this flash system is using FCM drives.

    I have never seen this before so following with interest, thanks Stuart



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    stuart wade
    Delivery Implementation Consultant
    Serviceexpress
    Bedford
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    Original Message


  • 3.  RE: Flashsystem 7300 not show written capacity

    Posted 2 days ago
    The "Not enough data" message in the "Written Capacity" column typically appears when FlashSystem has not yet observed sufficient I/O activity on a given volume to calculate data reduction statistics.
    In other words, FlashSystem is waiting for measurable physical write patterns before it can start reporting actual usage and reduction efficiency.
     
    For example: You assigned 1.65 TB of capacity to VMs from IBM7300-lun-10-TB-10, but the current free capacity is 9.34 TB.
    This means although 1.65 TB is provisioned and only about 675 GB is actually consumed by the VMs - but that's not yet reflected in the system's statistics due to insufficient data activity.
     
    Another example: On IBM7300-lun-10-TB-09, you've assigned 1.67 TB to VMs.
    The free space is 9.27 TB, so around 747.5 GB has been consumed.
    FlashSystem shows 523.30 GiB (561.8 GB) as physically written, giving an approximate compression ratio of 1.33:1 (approx 25%) space savings.
     
    So, "Not enough data" really means "Not enough data to feed my stats yet" 


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    Nezih Boyacioglu
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    Original Message


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