Netezza Performance Server

 View Only
Expand all | Collapse all

Percentage limit of NPS total Storage Usage.

  • 1.  Percentage limit of NPS total Storage Usage.

    Posted Wed February 07, 2024 06:26 AM

    Hi All,

    Is there a limit on the Total Storage Usage Percentage on NPS? Below which it is not possible to go down?

    On my NPS Production Environment by executing the command /nz/support/bin/nz_storage_stats

    it results Remaining about 19% 

    Total Storage
         Available        (TiB)   134.128
        .....
    .................
        Remaining          (%)   19.065

    Which is the Percentage limit?

    Thanks all.

    Bye
    Andrea



    ------------------------------
    Andrea Ceccotti
    ------------------------------


  • 2.  RE: Percentage limit of NPS total Storage Usage.

    Posted Tue March 12, 2024 08:09 AM

    Hi
    As far I'm aware there was no limit to Database/Data size in Netezza systems: except physical storage capacity. 
    Since NPS / (CP4D) share vast majority of the code with Netezza: I presume it's the same. 
    That is why is so important to keep your data "clean":
    - groom tables (with proper backup/groom sequence or just go for BACKUPSET NONE)
    - use distribute on random and enable random dist chunk
    - for small tables do not use distribution organization (otherwise will use 3MB on every dataslice)
    - developers have nasty tendency to spawn objects (tables) everywhere: drop those on sight (if nobody admit using it: check first in HISTDB what/who/why?)





    ------------------------------
    Adam Matusewicz
    ------------------------------



  • 3.  RE: Percentage limit of NPS total Storage Usage.

    Posted Tue March 12, 2024 11:48 AM
    Hi Adam,

    thanks a lot for your answer what I need to know is what percentage of usage or free can be reached on storage. This is my current situation on NPS Production Appliance:
    Total Storage
         Available        (TiB)   134.128
         Allocated        (TiB)   102.472
         Allocated          (%)   76.399
         Remaining        (TiB)   31.656
         Remaining          (%)   23.601

    For Remaining percentage now at 23% but we arrived to 18% how is the limit before Netezza stops itself, if I remember well it does not arrive to 0% or close to it, it stops before.

    What doo you mean for 
    - for small tables do not use distribution organization (otherwise will use 3MB?

    Thanks a lot.

    Bye 
    Andrea





  • 4.  RE: Percentage limit of NPS total Storage Usage.

    Posted Tue March 12, 2024 12:01 PM

    Hi Andrea
    If system will reach 100% on single dataslice: it will stop (as Huw wrote in other post). Check output of nz_skew and redistribute table(s) with large skew to random or choose better distrubution keys. 

    As for 3MB: when table have distribution it is by default allocated 3MB extent on every dataslce: regardless it will use them or not. 
    We saw many occasions where customers kept small tables (for example country codes, postal codes etc.) and used distrubtion on one column: so small few KB table were distributed on all dataslices and (depending on your system size) used 200-500 MB instead keeping it on single dataslice - use 3MB and broadcast table data when needed from single dataslice instead all of them. 



    ------------------------------
    Adam Matusewicz
    ------------------------------



  • 5.  RE: Percentage limit of NPS total Storage Usage.