6 Replies Latest reply: Aug 27, 2013 6:10 AM by Billy~Verreynne RSS

    Oracle Database on VMware

    user2728448

      The new direction within my IT organization is to start building all non-tier-1 Oracle databases on VMware.  I'm interested in any feedback this community has on experience with this design.

       

      Are there any specific reservations people have?  Any key areas that have shown to be problematic (e.g. performance degradation)?  Any existing benchmark analysis or artifacts that my team can refer to that highlight potential pitfalls?

       

      A handful of people have reservations about this approach, so any information or feedback would be appreciated.  Thanks.

        • 1. Re: Oracle Database on VMware
          sb92075

          user2728448 wrote:

           

          The new direction within my IT organization is to start building all non-tier-1 Oracle databases on VMware.  I'm interested in any feedback this community has on experience with this design.

           

          Are there any specific reservations people have?  Any key areas that have shown to be problematic (e.g. performance degradation)?  Any existing benchmark analysis or artifacts that my team can refer to that highlight potential pitfalls?

           

          A handful of people have reservations about this approach, so any information or feedback would be appreciated.  Thanks.

          user2728448 wrote:

           

          The new direction within my IT organization is to start building all non-tier-1 Oracle databases on VMware.  I'm interested in any feedback this community has on experience with this design.

           

          Are there any specific reservations people have?  Any key areas that have shown to be problematic (e.g. performance degradation)?  Any existing benchmark analysis or artifacts that my team can refer to that highlight potential pitfalls?

           

          A handful of people have reservations about this approach, so any information or feedback would be appreciated.  Thanks.

           

          I would have expected these type of questions to have been asked BEFORE the decision was made; not after.

          Apparently those making this choice know more than you on this topic.

           

          IMO, it is easy to overload the hardware & end up with performance problems which can be a challenge to determine which VM is causing problems for others on the same system.

          • 2. Re: Oracle Database on VMware
            rp0428
            The new direction within my IT organization is to start building all non-tier-1 Oracle databases on VMware.

            And what was the reason for that decision? What did the decision maker say when you ask them your question and problematic areas?

             

            Certainly no one with any real experience or credentials would make such a decision without carefully evaluating the possible problems that might result, would they?

            A handful of people have reservations about this approach, so any information or feedback would be appreciated.  Thanks.

            And why are you keeping those 'reservations' a secret'? Why didn't you post what reservations you are talking about so people can comment on them?

            Are there any specific reservations people have?  Any key areas that have shown to be problematic (e.g. performance degradation)?  Any existing benchmark analysis or artifacts that my team can refer to that highlight potential pitfalls?

            Sure

             

            1. The more 'layers' in the architecture the more things there are that can fail or be configured wrong. With VM you often now have

              a. The base OS

              b. TheVM kernel

              c. One or more virtual machines running under the VM kernel

              d. A VM  module to communicate with other VM modules

              e. The failure of the base server of VM kernel can now cause ALL of the virtual machines to fail instead of just one

             

            In addition you have the same issues that you have with any 'shared server': one process can hog the resources and starve the other processes. Do you really want a non-critical application to potentially cause problems for a critical application running on the same server on in the same VM kernel?

            • 3. Re: Oracle Database on VMware
              Srini Chavali-Oracle

              Pl also review MOS Doc 249212.1

               

              HTH
              Srini

              • 4. Re: Oracle Database on VMware
                Billy~Verreynne

                user2728448 wrote:

                 

                The new direction within my IT organization is to start building all non-tier-1 Oracle databases on VMware.  I'm interested in any feedback this community has on experience with this design.

                 

                Are there any specific reservations people have?  Any key areas that have shown to be problematic (e.g. performance degradation)?  Any existing benchmark analysis or artifacts that my team can refer to that highlight potential pitfalls?

                 

                A handful of people have reservations about this approach, so any information or feedback would be appreciated.  Thanks.

                 

                It is no different (from an Oracle db perspective), than running on a bare metal o/s. The same performance and resource considerations apply. So you want sufficient CPU horses and sufficient memory in the VM for Oracle.

                 

                This is also not your regular VirtualBox style VM. It is (should/must be) a VM hypervisor that runs the VM. There are minimal moving parts between VM and bare metal.

                 

                Add to this h/w designed for this exact purpose, and you have a VM that should not only be as fast as your current bare metal servers, but also scalable (more CPUs and memory can be allocated to the VM), and with advantages not found using bare metal (like VM snapshots, etc).

                 

                So virtualisation of a RDBMS server is not a Bad Thing (tm). Like any other h/w architecture, it needs to be well designed and implemented. And that is perhaps where the crux of the problem is - giving rise to the hesitation of using virtualisation.

                 

                You also need to virtualise the most appropriate platforms. I would not virtualise RAC - despite the claims and white papers of virtualisation vendors. Virtualisation cannot give me 40Gb Infiniband and RDS. Virtualisation cannot give me dedicated dual 8Gb fibre channels.

                 

                Any specific VM h/w technology your company is considering, like UCS or Exadata/Exalogic for example?

                • 5. Re: Oracle Database on VMware
                  Stefan Koehler

                  Hi,

                   

                  >  I'm interested in any feedback this community has on experience with this design.

                  Yes, i have done several projects in this area (database consolidation on central VMware infrastructures) and it runs awesome even for performance critical databases / applications, if it is planned and implemented very well.

                   

                  > A handful of people have reservations about this approach, so any information or feedback would be appreciated.

                  Well, it is normal and not only VMware / Oracle related. Every new technology raises some concerns until it is proofed that it works well.

                   

                  > Pl also review MOS Doc 249212.1

                  That note is fine, but has no "relevance" in real life. There is an official statement by Günther Stürner, that Oracle is supported on VMware, but in the very rare cases you need to reproduce it on native hardware. But this is also no limitation at all (especially not when using Linux as guest OS), because of you can implement a dual boot solution with nearly no extra effort by using a custom initrd image or tools like Comoonics.

                   

                  > Virtualisation cannot give me dedicated dual 8Gb fibre channels.

                  That is not true. You can use RDM (Raw Device Mapping) on VMware with dedicated FCs (by SAN zoning) and so you have all the SCSI stuff available in the VM and it is dedicated as well. Other virtualization technologies (like on IBM power architecture) allow the same.

                   

                  > Any key areas that have shown to be problematic (e.g. performance degradation)?

                  Of course - and this is why i mentioned, that it needs to be planned very well. You will have some CPU overhead on VMware (in my experience round about 3% with Oracle databases on new x86 CPU types) and you need to consider the memory handling and mapping (check out my blog and this VMware white paper about TLB handling). There are also some I/O boundaries (if these are reached virtualization makes no sense at all) and i am not talking about I/O throughput or capacity only - you need to consider B2B credits as well and so on. It also depends on your key infrastructure components like storage sub system. There are a lot of "best practices", but every customer environment is different and so you need to analyze your infrastructure and do the best for your configuration.

                   

                  Regards

                  Stefan

                  • 6. Re: Oracle Database on VMware
                    Billy~Verreynne

                    StefanKoehler wrote:

                    > Virtualisation cannot give me dedicated dual 8Gb fibre channels.

                    That is not true. You can use RDM (Raw Device Mapping) on VMware with dedicated FCs (by SAN zoning) and so you have all the SCSI stuff available in the VM and it is dedicated as well. Other virtualization technologies (like on IBM power architecture) allow the same.

                     

                    Have use raw device mapping on VMware (ESS or w/s I think) in the past - useful for booting the 2nd natively installed o/s on the same machine (Windows NT was especially easy to boot this way as you could create a 2nd NT profile for the virtual h/w to boot from).

                     

                    My point is that VMs are typically deployed at many-to-one to bare metal. So I expect that my VM will not be the single sole VM on that server - which by implication means that my VM will be sharing the bare metal Fibre Channels with other VMs on that server.

                     

                    And for RAC specifically, I do not want to, or see the benefits of, share the same h/w like CPUs, RAM, HBAs and HCAs between different RAC nodes.

                     

                    I have read the white paper for RAC on VM for UCS. I am not convinced.