1 2 Previous Next 20 Replies Latest reply: May 25, 2012 8:10 AM by Srini Chavali-Oracle RSS

    Migration Issues

    788793
      Hi All,

      Migrating a db through exp/imp from 10.2.0.1(32Bit) to 11.2.0.3 (64 Bit) New server. DB size is 140G. The mount points in old server and new server are different.
      Have the following questions;

      1) If I use exp/imp what is the approx time (any benchmark) taken to take the backup?
      (Server has 4 processors/3G RAM)

      2) Taking a full DB export. Do I have to create users/schemas and Tablespaces as per old server in New server ?
      If I dont create users and Tablespaces what will happen

      3) Before I cut-off to production I have to take the incremental backup again. In that case can I use exp (inc_type) and expdp(flashback_scn) or Rman incremental. ?
        • 1. Re: Migration Issues
          AliD
          1) If I use exp/imp what is the approx time (any benchmark) taken to take the backup?
          (Server has 4 processors/3G RAM)>
          No one can tell! it could be anything from 30mins to 6 hours. Depending on many many parameters.
          2) Taking a full DB export. Do I have to create users/schemas and Tablespaces as per old server in New server ?
          If I dont create users and Tablespaces what will happen>
          If you don't create them, imp will try to create them in original mount point and will fail.
          3) Before I cut-off to production I have to take the incremental backup again. In that case can I use exp (inc_type) and expdp(flashback_scn) or Rman incremental. ?
          RMAN won't work. Inc_type is a dummy parameter. Good luck with flashback_scn. You gotta extract the incremental data somehow with queries. You probably are better off with another full import.
          • 2. Re: Migration Issues
            Rodriguez
            Since you have multiple processors and big Ram In your case I suggest you to use vast utilities EXPDP / IMPDP .
            To make a process faster you can use parallel option
            ( which ,I think ,doesn't exist in simple exp utility) and special type of dumpfile parameter.
            On another side you can manage with data however you want .
            • 3. Re: Migration Issues
              494959
              1- Import/export execution time we cannot estimate.

              2-take a full data base export (exp/expdp), before importing create the same set up (users/tablestrucutre), You use remap faciltiy also if you username/tablespace differs.

              3- Full database back up will help in you migration activity.If you have incremental backup there is more work need to do.
              • 4. Re: Migration Issues
                Srini Chavali-Oracle
                Pl post exact OS versions on source and target. How much down time can you afford ?

                HTH
                Srini
                • 5. Re: Migration Issues
                  788793
                  Hi Srini,

                  Source - Oracle 10.2.0.1 32 Bit on RHEL 5

                  Target - Oracle 11.2.0.3 64 Bit on RHEL 5.6

                  Approved Downtime - < 4Hrs.
                  • 6. Re: Migration Issues
                    Srini Chavali-Oracle
                    You will likely not achieve export/import in 4 hours.

                    One alternative is to break this work into two pieces - (1) upgrade to 11.2.0.3 on the current server (expected downtime will be about 6 hours) and (2) move/clone the upgraded database and oracle binaries to the new server (outage should be a few hours), or

                    (1) move/clone existing database and oracle binaries to new server and (2) upgrade to 11.2.0.3 on the new server.

                    This will require two downtime windows - with a total downtime of approx 9-12 hours.

                    HTH
                    Srini
                    • 7. Re: Migration Issues
                      788793
                      Srini,

                      1> Option 1 cannot. The production server should be online except small downtime window.

                      2) Option 2: Using that. But u can't upgrade from 10.2.0.1 to 11.2.0.3 straightaway. First need to patch up to 10.2.0.2 or 10.2.0.4

                      Edited by: user13355115 on May 23, 2012 8:03 AM
                      • 8. Re: Migration Issues
                        Srini Chavali-Oracle
                        You are correct in that you need to be at least at 10.2.0.2 to upgrade to 11.2.0.3 via DBUA or scripts (http://docs.oracle.com/cd/E11882_01/server.112/e23633/preup.htm#i1007814)

                        So this will add an additional step to the process. In both the scenarios outlined above, the total downtime (in two separate chunks) will be approximately the same. You now have to add a third chunk (upgrade to 10.2.0.2 or later).

                        I do not believe all of this can be accomplished in 4 hours

                        HTH
                        Srini
                        • 9. Re: Migration Issues
                          788793
                          Srini,

                          But if I use exp/imp or data pump I do not need to patch up. Only clone/rman backups need this.
                          Correct me if I am wrong.

                          Also when I cut-off for production I need to take the latest backup/incremental again. What possibilities of incremental backups do I have in logical backups?

                          I am not preferring RMAN since the bit-rate is different and it can fail in this scenario.
                          • 10. Re: Migration Issues
                            Srini Chavali-Oracle
                            If you are wanting to use exp/imp, then the downtime will be far longer than 4 hours. You will have to do a test run to determine how long the instance will need to be down. If this downtime is acceptable, then exp/imp is the way to go

                            HTH
                            Srini
                            • 11. Re: Migration Issues
                              788793
                              Srini,

                              But how to take the incremental backups through exp/imp or data pump..
                              • 12. Re: Migration Issues
                                ora_tech
                                Hi,

                                Plz refer this thread:

                                Incremental exports using exp utility in 9i

                                thanks,
                                X A H E E R
                                • 13. Re: Migration Issues
                                  Srini Chavali-Oracle
                                  Pl define what you mean by "incremental" - I do not believe this feature is supported by exp or expdp

                                  HTH
                                  Srini
                                  • 14. Re: Migration Issues
                                    788793
                                    Srini,

                                    What I mean is;

                                    Initially w'll take a exp dump and import in New Server.

                                    Later (within 1/2 days) we have to imp the additional/incremental data from the old server to sync the old/new servers.

                                    So how do we do that ??
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