6 Replies Latest reply on Oct 1, 2012 12:06 PM by ggworthy

    SCAN Configuration

    ggworthy
      We have a 2 node RAC that is being currently setup with a SCAN using /etc/hosts and it looks as below.

      10.20.13.48 nodedb.lausd.net nodedb
      10.20.13.46 nodeda.lausd.net nodeda
      10.20.13.47 nodeda-vip.lausd.net nodeda-vip
      10.20.13.49 nodedb-vip.lausd.net nodedb-vip
      172.20.3.19 nodeda-nfs.lausd.net nodeda-nfs
      172.20.3.66 nodedb-nfs.lausd.net nodedb-nfs

      10.20.13.50 noded-scan.lausd.net noded-scan

      Now I want the SCAN to use DNS instead of /etc/hosts/ as above in both the nodes.

      1.Do I need to get additional IP addresses , as oracle recommends 3 ips for SCAN
      2. What is the step by step procedure to go from /etc/hosts to using DNS.

      Please help me with this.

      Thanks
        • 1. Re: SCAN Configuration
          onedbguru
          ggworthy wrote:
          We have a 2 node RAC that is being currently setup with a SCAN using /etc/hosts and it looks as below.

          10.20.13.48 nodedb.lausd.net nodedb
          10.20.13.46 nodeda.lausd.net nodeda
          10.20.13.47 nodeda-vip.lausd.net nodeda-vip
          10.20.13.49 nodedb-vip.lausd.net nodedb-vip
          172.20.3.19 nodeda-nfs.lausd.net nodeda-nfs
          172.20.3.66 nodedb-nfs.lausd.net nodedb-nfs

          10.20.13.50 noded-scan.lausd.net noded-scan

          Now I want the SCAN to use DNS instead of /etc/hosts/ as above in both the nodes.

          1.Do I need to get additional IP addresses , as oracle recommends 3 ips for SCAN
          Yes. You need 3. Once DNS is configured, comment out the /etc/hosts scan address and follow the instructions to add the additional scan listeners
          2. What is the step by step procedure to go from /etc/hosts to using DNS.
          http://www.lmgtfy.com/?q=oracle+scan+pdf <<-- follow this document to ensure you configured scan correctly.
          http://www.lmgtfy.com/?q=oracle+srvctl+modify+scan

          >
          Please help me with this.

          Thanks
          • 2. Re: SCAN Configuration
            ggworthy
            If use just one IP instead of three, what will be the impact ?Will it stop working ?
            • 3. Re: SCAN Configuration
              Aman....
              ggworthy wrote:
              If use just one IP instead of three, what will be the impact ?Will it stop working ?
              No, it won't stop and if you are using DNS, its up to you to have configured how many SCAN VIP's you want. Only one is enough, that's about it! More than one can be there and in the case of DNS, its you who have to decide how many you want. Oracle recommends to have three as more than that won't be proving to be really useful much. That's why they mention that should use 3 and in the case of GNS , its already being set to 3 as maximum.

              Aman....
              1 person found this helpful
              • 4. Re: SCAN Configuration
                ggworthy
                Thanks everyone and appreciate your responses
                • 5. Re: SCAN Configuration
                  ggworthy
                  Thanks everyone and appreciate your responses
                  • 6. Re: SCAN Configuration
                    ggworthy
                    Thanks everyone. Appreciate your responses