2 Replies Latest reply: Apr 27, 2012 5:30 AM by Ilmar.Kerm RSS

    ASM configuration for multiple databases - best practices?

      Hi guys,

      I was just trying to find some material on the recommended guidelines when deploying ASM thats shared among multiple databases, eg: I have 1 ASM instance that has several large diskgroups, to be shared by 5 or more databases. I've implemented multiple ASM instances (for both single-instance and RAC) without issues, but I was wondering if there's any guidelines to follow when sharing an instance among many databases, for example if I want to have 10 DBs sharing my ASM diskgroups on a single ASM instance, how many processes do i need to define for the ASM instance? What is the max number of connections that a single diskgroup can support at a time (and is there any way to verify this), etc etc

      Any pointers would be appreciated, thanks
        • 1. Re: ASM configuration for multiple databases - best practices?
          I think for our systems we typically do one instance with multiple disk groups per database. ie.



          This makes things a lot easier to manage, especially if you get rid of a DB and don't want it to affect the others.
          • 2. Re: ASM configuration for multiple databases - best practices?
            Take a look at http://docs.oracle.com/cd/E11882_01/server.112/e18951/asminst.htm#BHCFHDDJ
            this gives you a formula to calculate PROCESSES parameter.

            There can be only one ASM instance per node, so if you have many database instances running on one node they must share the same ASM instance and there is no problem with that.

            Note "ASM Technical Best Practices [ID 265633.1]" states that "Oracle generally recommends no more than two diskgroups." So different databases can share common disk groups easily and it makes administration tasks much easier. I have usually created additional TEMP diskgroup for storing tempfiles, because tempfiles could be excluded from storage replication to standby site.