12 Replies Latest reply: Aug 13, 2012 2:04 AM by UweHesse RSS

    Backing Up Exadata Cell Software

    954526
      Hello,
      1) I have half rack of X2-2. I am wondering that is there any need of taking backup of software at the cell? Or is it done automatically? If there is need of backup then how should I go about it?

      2) Can I specify the interleaving of griddisk through ASM, or can it only be done while creating the cell disks?

      Thanks.
        • 1. Re: Backing Up Exadata Cell Software
          Dan.Norris-Oracle
          951523 wrote:
          Hello,
          1) I have half rack of X2-2. I am wondering that is there any need of taking backup of software at the cell? Or is it done automatically? If there is need of backup then how should I go about it?
          You need not make backups of the storage cell OS or software. It is backed up and restorable from a small internal USB drive installed in each storage cell. The contents of the USB are maintained automatically and the storage cell admin guide describes how to use the rescue mode on the cell to recover the OS and software in the event you need to.

          >
          2) Can I specify the interleaving of griddisk through ASM, or can it only be done while creating the cell disks?
          Have you seen a significant impact by using interleaving?
          • 2. Re: Backing Up Exadata Cell Software
            954526
            Dan.Norris wrote:
            951523 wrote:
            Hello,
            1) I have half rack of X2-2. I am wondering that is there any need of taking backup of software at the cell? Or is it done automatically? If there is need of backup then how should I go about it?
            You need not make backups of the storage cell OS or software. It is backed up and restorable from a small internal USB drive installed in each storage cell. The contents of the USB are maintained automatically and the storage cell admin guide describes how to use the rescue mode on the cell to recover the OS and software in the event you need to.
            2) Can I specify the interleaving of griddisk through ASM, or can it only be done while creating the cell disks?
            Have you seen a significant impact by using interleaving?
            Hi Dan, thanks for your answers. My question is just academic as I know that its best to leave the grididisks at default and rarely if ever they need to be interleaved. I am just curious as is there any way to specify interleaving through ASM, instead of specifying it when creating cell disks? Thanks
            • 3. Re: Backing Up Exadata Cell Software
              andy.colvin
              Since the interleaving is done at the griddisk level, it wouldn't be possible to do it through ASM. It's a good idea to name your griddisks after the ASM diskgroup that will reside on them, so you would need different griddisk prefixes to represent the different diskgroups in your ASM instance.
              • 4. Re: Backing Up Exadata Cell Software
                954526
                Thanks Andy, please clear one more confusion. Is the interleaving is specified while creating celldisks or while creating griddisks? It think its while creating celldisks, right?

                Thanks.
                • 5. Re: Backing Up Exadata Cell Software
                  andy.colvin
                  It would happen at the griddisk level. Basically, the concept is to create 2 diskgroups with similar performance in the space where you would normally have one diskgroup. To achieve this, you would have griddisks alternating between the inside and outside portions of each celldisk. The process is described in more detail in the "Expert Oracle Exadata" book.
                  • 6. Re: Backing Up Exadata Cell Software
                    954526
                    Thanks Andy for your answer.

                    I found the following somewhere at the web:

                    CELLCLI> Create celldisk interleaving_test lun=0_11, INTERLEAVING='normal_redundancy'

                    so doesn't above mean that we specify interleaving at the time of celldisk creation?

                    Thank you.
                    • 7. Re: Backing Up Exadata Cell Software
                      User227901
                      1) I have half rack of X2-2. I am wondering that is there any need of taking backup of software at the cell? Or is it done automatically? If there is need of backup then how should I go about it?
                      There is no need to back the cell software, it is automatically backed up into INTERNAL USB called CELLBOOT USB FLASH drive. The software is available in first two disks of the cell.
                      Also if these two disks go bad, the cell gets booted by using the backup it has on the flash.
                      But oracle also provides you an option to backup using Logical volume manager, Also you can backup externally, it goes to USB plugged to the first port on your exadata machine.

                      2) Can I specify the interleaving of griddisk through ASM, or can it only be done while creating the cell disks?

                      You can only create interleaving griddisk using cellcli, and this can be only done during celldisk creation.

                      Edited by: 873350 on Aug 9, 2012 12:23 AM
                      • 8. Re: Backing Up Exadata Cell Software
                        954526
                        873350 wrote:
                        But oracle also provides you an option to backup using Logical volume manager, Also you can backup externally, it goes to USB plugged to the first port on your exadata machine.
                        Can you explain in bit detail please as what do you mean by backing it up externally?

                        Thanks.
                        • 9. Re: Backing Up Exadata Cell Software
                          Dan.Norris-Oracle
                          Mark Martin wrote:
                          873350 wrote:
                          But oracle also provides you an option to backup using Logical volume manager, Also you can backup externally, it goes to USB plugged to the first port on your exadata machine.
                          Can you explain in bit detail please as what do you mean by backing it up externally?
                          This thread has started to mix storage cell backups with DB node backups. To clarify things, here are the options available:

                          On storage cells, you need not backup the OS as the OS is backed up internally using an internal USB drive inside the machine automatically. This internal USB drive is updated whenever there are software upgrades or configuration changes on the cell, so it is completely self-maintained. There are no other options available to back up the storage cells.

                          On DB nodes, you may use whatever backup software you choose including enterprise backup software that requires agent installs (as most of them do). You may also follow the instructions in the owner's guide to create snapshot backups of the filesystems, though those backups still reside inside the machine, so don't provide protection in the event of a complete loss of a node. You may also devise whatever other backup scheme you wish including ones that require software to be installed on the DB node. The limitation is that you can't alter or install hardware in any node of the database machine, so you can't install things like a controller for a tape drive or fibre channel cards to communicate with other enterprise storage.
                          • 10. Re: Backing Up Exadata Cell Software
                            tychos
                            Hi Mark Martin,
                            Can you explain in bit detail please as what do you mean by backing it up externally?
                            If you have the Exadata documentation available.
                            Open Exadata Storage Server Software User's Guide
                            Scroll to:
                            Maintaining Oracle Exadata Storage Server Software
                            Read the section:
                            make_cellboot_usb utility
                            Regards,
                            Tycho
                            • 11. Re: Backing Up Exadata Cell Software
                              954526
                              Hello,
                              Thanks Dan and Tychos for your answers. Backup thing is clear, please just confirm the following:



                              CELLCLI> Create celldisk interleaving_test lun=0_11, INTERLEAVING='normal_redundancy'

                              so doesn't above mean that we specify interleaving at the time of celldisk creation?

                              regards
                              • 12. Re: Backing Up Exadata Cell Software
                                UweHesse
                                It is true that you have to specify interleaving already when you create the celldisks. The griddisks that you create subsequently upon those interleaved celldisks will have similar performance. Otherwise (without interleaved celldisks) the first griddisk will have better performance than the second, because it will be carved out of the outer sector of the spinning disk completely. See here for a more detailed description:
                                http://uhesse.com/2011/05/18/exadata-part-vii-meaning-of-the-various-disk-layers/

                                It seems that interleaving is done very rarely, though.

                                Kind regards
                                Uwe Hesse

                                "Don't believe it, test it!"
                                http://uhesse.com