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  • 15. Re: Is Interconnect mandatory in ORACLE RAC??
    979594 Newbie
    Currently Being Moderated
    Hi Gurus,

    Generally, a RAC Setup contains multiple nodes with a single database , whose instances are shared across all the nodes... and interconnect serves the purpose of Cache Coherency and internode communications..

    What if there is only one node , one instance RAC Environment ....

    Should Interconnect be mandatorily implemented to install Clusterware, GI, ASM etc on a single node.. (Please do not confuse with One Node RAC), i am talking about Single instance RAC.

    Cheers,

    Sash.
  • 16. Re: Is Interconnect mandatory in ORACLE RAC??
    BillyVerreynne Oracle ACE
    Currently Being Moderated
    976591 wrote:

    What if there is only one node , one instance RAC Environment ....

    Should Interconnect be mandatorily implemented to install Clusterware, GI, ASM etc on a single node.. (Please do not confuse with One Node RAC), i am talking about Single instance RAC.
    The Interconnect is a mandatory installation option - in that you need to choose the IP interface to use as Interconnect. This step cannot be skipped. However, whether that interface is part of a robust and scalable Interconnect architecture, is the user's responsibility.
  • 17. Re: Is Interconnect mandatory in ORACLE RAC??
    hitgon Expert
    Currently Being Moderated
    Is crossover cable supported as an interconnect with RAC on any platform ?

    NO. CROSS OVER CABLES ARE NOT SUPPORTED. The requirement is to use a switch:

    Detailed Reasons:

    1) cross-cabling limits the expansion of RAC to two nodes

    2) cross-cabling is unstable:

    a) Some NIC cards do not work properly with it. They are not able to negotiate the DTE/DCE clocking, and will thus not function. These NICS were made cheaper by assuming that the switch was going to have the clock. Unfortunately there is no way to know which NICs do not have that clock.

    b) Media sense behavior on various OS's (most notably Windows) will bring a NIC down when a cable is disconnected. Either of these issues can lead to cluster instability and lead to ORA-29740 errors (node evictions).

    Due to the benefits and stability provided by a switch, and their afforability ($200 for a simple 16 port GigE switch), and the expense and time related to dealing with issues when one does not exist, this is the only supported configuration.

    From a purely technology point of view Oracle does not care if the customer uses cross over cable or router or switches to deliver a message. However, we know from experience that a lot of adapters misbehave when used in a crossover configuration and cause a lot of problems for RAC. Hence we have stated on certify that we do not support crossover cables to avoid false bugs and finger pointing amongst the various parties: Oracle, Hardware vendors, Os vendors etc...
  • 18. Re: Is Interconnect mandatory in ORACLE RAC??
    AnkitAshokAggarwal Explorer
    Currently Being Moderated
    Kindly see my reply to this post for answer.
    this is solve now.
    yes it is must as for two most important components of RAC : shared storage and global cache.
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