Hitachi Ops Center​

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  • 1.  consistency on while allocating new gad vols

    Posted 06-07-2023 05:11

    have couple of vm servers need to give vols first time will use gad but not sure is it ok to keep consistency  option on any harm if kept on



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    dhruv kalia
    System Administrator
    EVRY AB
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  • 2.  RE: consistency on while allocating new gad vols

    Posted 06-07-2023 06:43

    here we get this while allocating pair



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    dhruv kalia
    System Administrator
    EVRY AB
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  • 3.  RE: consistency on while allocating new gad vols

    Posted 06-08-2023 03:14

    Hello

    Consistency groups are required if you want to make sure that the volumes stay in step with one another. It also forces them to be part of the same 'batch process'. IE, you have to make all of them in a single consistency group group replication one way or another but you cant mix replication directions within the same consistency group. Great use case for when you have database volumes, having your logs and database volumes in the same consistency group.

    Word of caution though, you have a limited number of consistency groups per system so if you don't need it between the volumes in question I would personally not recommend it. It adds a little bit of overhead on the system since the storage system needs to keep track of the IO sequence between the volumes. 

    Have a look here for some additional info:

    https://knowledge.hitachivantara.com/Documents/Management_Software/Ops_Center/10.9.x/High_Availability/Overview_of_global-active_device/08_GAD_consistency_groups



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    William Jansen Van Nieuwenhuizen
    Hitachi Vantara
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  • 4.  RE: consistency on while allocating new gad vols

    Posted 06-08-2023 08:35
    Many thanks for your response so we use it for db servers i think if disaster happens the impact will be on both vols at same time