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Migrating 18c from Oracle Linux 6 to 7

chrisseon
chrisseon Member Posts: 26
edited May 30, 2020 1:28PM in Database Upgrade

Hi,

Our 18c databases are currently on NetApp and HPE and we are planning to migrate the databases from the existing server running Oracle Linux 6 to a new server running Oracle Linux 7. Would it be possible to simply unmount the data file directories on Linux 6 and mount it to the new server running Linux 7? If that is not possible due to the differing OS versions, what would be the fastest way to migrate the data over to the new OS? Trying to avoid data dump.

Thanks.

Best Answer

  • Daniel Overby Hansen-Oracle
    Daniel Overby Hansen-Oracle Posts: 93 Employee
    edited May 24, 2020 3:52PM Answer ✓

    Hi,

    Yes, you can just take the data files and use them directly on the new system. It makes no difference what version of Oracle Linux that you use.

    I would prefer setting up a data guard on your new system. You can do that without down time and you can test that it works, do full backups etc. while the old system is still running. When you want to make the switch you can just do a SWITCHOVER to the data guard and now you are running on the new system. It should only take a few minutes to complete - there will be no more downtime.

    Then you can have the old system running as the data guard for a while until you are confident with the new system performance.

    Regards,

    Daniel

Answers

  • Daniel Overby Hansen-Oracle
    Daniel Overby Hansen-Oracle Posts: 93 Employee
    edited May 24, 2020 3:52PM Answer ✓

    Hi,

    Yes, you can just take the data files and use them directly on the new system. It makes no difference what version of Oracle Linux that you use.

    I would prefer setting up a data guard on your new system. You can do that without down time and you can test that it works, do full backups etc. while the old system is still running. When you want to make the switch you can just do a SWITCHOVER to the data guard and now you are running on the new system. It should only take a few minutes to complete - there will be no more downtime.

    Then you can have the old system running as the data guard for a while until you are confident with the new system performance.

    Regards,

    Daniel

  • Dude!
    Dude! Member Posts: 22,830 Black Diamond
    edited May 24, 2020 7:19PM

    If there are potential pitfalls then certainly not mounting a filesystem you used in a previous release version. OL 7 defaults to XFS, but it can still use EXT. Depending on what you use, however, you may have to import the LVM configuration and work out the storage controller/network configuration. So the process can be somewhat more complex than simply "mounting."

    Your concern should be Oracle database and kernel compatibility. Since you have not given any details... Please check the the Oracle database installation documentation for system requirements. You may require a database patch or upgrade. You will at least need Oracle database 11.2.0.4 or Enterprise Linux 7.

  • Dude!
    Dude! Member Posts: 22,830 Black Diamond
    edited May 25, 2020 8:30AM

    I recall a past discussion about licensing requirements for Dataguard for the purpose of migrating. I haven't check recently, but it seems there used to be something about 10 days, but no official statement or documentation. When you work at Oracle, I suppose you don't have to worry. Fortunately or unfortunately Oracle makes it easy to exceed license requirements. I guess when you are in the cloud, there's no more hiding or escaping.

  • Daniel Overby Hansen-Oracle
    Daniel Overby Hansen-Oracle Posts: 93 Employee
    edited May 25, 2020 8:07AM

    The 10 days rule are only for certain cluster solutions and does not apply in this scenario. Data Guard comes as part of your Enterprise Edition but you need to license the data guard hardware as well. If that is a problem to you I am sure that you can work out something with your sales rep. From the top of my head, I am aware of several migration projects where this was not an issue.

    Regards,

    Daniel

  • Dude!
    Dude! Member Posts: 22,830 Black Diamond
    edited May 25, 2020 8:52AM

    Thanks for the info! I guess one day Oracle will have to go easy on licensing. Who will still want to pay all this money for software licensing in the future? There are alternatives available that cost much less and the argument of supporting Linux no longer matters.