Centera Object Count Question

Question

Hi All, I have a Centera and while capacity planning to project when we may run out of available objects, I have confused myself.  When I look at the 'show pool capacity' output I see the following: Config# show pool capacity Capacity / Pool      Quota      Used       Free       C-Clips     Files ------------------------------------------------------------------------------ ConsoleArchive       --         101 MB     --         1577        1 AuditArchive         --         774 MB     --         579460      0 APP1_pool            81,920 GB  82,769 GB  --         31609130    31609130 APP2_pool            20,480 GB  186 GB     20,294 GB  55907829    55907829 default              --         0 GB       --         0           0 SystemArchive        --         0 GB       --         0           0                                                                               Total                --         82,956 GB  --         88097996    87516960 ------------------------------------------------------------------------------ Here I see that the pools have used 88 Million total  C-Clips and 87.5 Million files. But when examining the 'show objects detail storage' output: Config# show objects detail storage Node     Roles          Status Total   Used    Supp    Free --------------------------------------------------------------- c001n01  A,M,R,S        on     50 M    4 M     50 M    46 M c001n02  A,M,R,S        on     50 M    5 M     50 M    45 M c001n03  A,M,R,S        on     50 M    5 M     50 M    46 M c001n04  A,M,R,S        on     50 M    5 M     50 M    46 M c001n05  S              on     50 M    4 M     50 M    46 M c001n06  S              on     50 M    4 M     50 M    46 M c001n07  S              on     50 M    4 M     50 M    46 M c001n08  S              on     50 M    4 M     50 M    46 M c001n09  S              on     50 M    5 M     50 M    46 M c001n10  S              on     50 M    4 M     50 M    46 M c001n11  S              on     50 M    4 M     50 M    46 M c001n12  S              on     50 M    4 M     50 M    46 M c001n13  S              on     50 M    4 M     50 M    46 M c001n14  S              on     50 M    4 M     50 M    46 M c001n15  S              on     50 M    4 M     50 M    46 M c001n16  S              on     50 M    4 M     50 M    46 M c002n01  A,M,R,S        on     50 M    4 M     50 M    46 M c002n02  A,M,R,S        on     50 M    4 M     50 M    46 M c002n03  A,M,R,S        on     50 M    4 M     50 M    46 M c002n04  A,M,R,S        on     50 M    4 M     50 M    46 M c002n05  S              on     50 M    4 M     50 M    46 M c002n06  S              on     50 M    4 M     50 M    46 M c002n07  S              on     50 M    6 M     50 M    45 M c002n08  S              on     50 M    4 M     50 M    46 M c002n09  S              on     50 M    4 M     50 M    47 M c002n10  S              on     50 M    4 M     50 M    46 M c002n11  S              on     50 M    4 M     50 M    47 M c002n12  S              on     50 M    4 M     50 M    46 M c002n13  S              on     50 M    4 M     50 M    46 M c002n14  S              on     50 M    4 M     50 M    46 M c002n15  S              on     50 M    4 M     50 M    46 M c002n16  S              on     50 M    4 M     50 M    46 M c003n01  S              on     50 M    5 M     50 M    46 M c003n02  S              on     50 M    5 M     50 M    45 M c003n03  S              on     50 M    5 M     50 M    45 M c003n04  S              on     50 M    5 M     50 M    45 M c003n05  S              on     50 M    4 M     50 M    46 M c003n06  S              on     50 M    5 M     50 M    46 M c003n07  S              on     50 M    5 M     50 M    45 M c003n08  S              on     50 M    4 M     50 M    46 M c003n09  S              on     50 M    6 M     50 M    45 M c003n10  S              on     50 M    5 M     50 M    45 M c003n11  S              on     50 M    6 M     50 M    44 M c003n12  S              on     50 M    5 M     50 M    46 M c003n13  S              on     50 M    8 M     50 M    42 M c003n14  S              on     50 M    9 M     50 M    41 M c003n15  S              on     50 M    8 M     50 M    42 M c003n16  S              on     50 M    9 M     50 M    41 M c004n01  S              on     50 M    9 M     50 M    41 M c004n02  S              on     50 M    9 M     50 M    41 M c004n03  S              on     50 M    9 M     50 M    41 M c004n04  S              on     50 M    9 M     50 M    41 M --------------------------------------------------------------- Total (online nodes: 52)       2,609 M 265 M   2,609 M 2,345 M Roles: A(ccess), M(anagement), R(eplication), S(torage) I can see that 265 Million objects have been used.  Where does the extra overhead come from to go from 88 Million objects to 265 Million objects?  Also I see that my system has a 2.609 BIllion object count.  I need to know how many files the Centera will be able to store by figuring out this used overhead. Thanks for the help.

srbhandary · Accepted Answer

Hello Nathan,

The difference of counts you notice with C-Clips and object counts is because Centera uses single instance storage and a c-clip can contain pointers to multiple blobs (objects) .

And the number of files the centera can store depends on the object count. As long as the object count threshold is not crossed (50M / node and configurable to 100M with assistance from EMC tech support) , you can keep storing files.

To understand the storage technology in Centera, see the EMC Centera Capacity Reporting for Gen4LP on CentrStar 4.0 guide on Powerlink. The document that has illustrations and examples.

You can find this White Paper on Powerlink at one of these locations:

Home > Products > Hardware/Platforms > Centera > White Papers

Home > Support > Technical Documentation and Advisories > White Papers > All White Papers

Centera

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