7 Replies Latest reply on Apr 19, 2016 5:46 PM by Intel Corporation

    RAID1 capacity

    cscarbro

      My system has two 1-TB HDD's installed.  In the Intel RSTe controller page, the size of each drive appears as 931.5 GB, which is expected.  Then if I configure these two HDD's into a RAID1 array, the maximum capacity shows as only 884.9 GB.  Is it expected behavior for each drive to lose nearly 50GB of available space when configuring a software RAID1 array?

       

      Any input would be appreciated.  Thanks.

        • 1. Re: RAID1 capacity
          Intel Corporation
          This message was posted on behalf of Intel Corporation

          Hello, cscarbro:


          Thank you for contacting the Intel Communities.


          As far as I know that is not expected, that amount of space should be less.


          My recommendation would be to backup your files and then perform a clean installation of windows, but before doing this, create the RAID configuration with CTRL + I if you are using and Intel board or the utility from the manufacturer of your Motherboard.


          The goal with that would be to format both drives and create the RAID before instaling windows*


          Additionally, I found this article that explains how the System Reserved Partitions work (this could be the partition that is taking that amount of space).


          http://www.howtogeek.com/192772/what-is-the-system-reserved-partition-and-can-you-delete-it/

          NOTE: This link is being offered for your convenience and should not be viewed as an endorsement by Intel of the content, products, or services offered there.


          If you require any further information or support, do not hesitate to contact us back.


          Regards,
          Esteban C

          • 2. Re: RAID1 capacity
            cscarbro

            Hello, Esteban,

             

            Thank you for the information.  This problem has not been seen on other RAID controllers (WebBios, MegaRAID) and seems to be independent of Windows.  We are configuring the RAID array before installing Windows, anyway.

             

            Is there any way we can tell what is causing this reduced capacity when we configure the RAID1 array, before we install any OS?

             

            Thanks,

            Chad

            • 3. Re: RAID1 capacity
              Intel Corporation
              This message was posted on behalf of Intel Corporation

              Hello, cscarbro:

              Thank you for your answer on this.

              I would like to request some information about your system.

              -OS:
              -CPU:
              -Motherboard Model:
              -BIOS Version:

              Regarding the behavior compared to the hardware RAIDs used, this is expected (the amount of storage used by the controller could be less than with a software RAID).

              I look forward to your answer on this.

              Regards,
              Esteban C

              • 4. Re: RAID1 capacity
                cscarbro

                Hello, Esteban,

                 

                If the RAID1 capacity of the software RAID controller is expected to be lower than hardware RAID, then what is that "missing" space in software RAID used for?

                 

                Here is the information you requested:

                 

                OS:  None (this RAID is configured before the OS is installed)

                CPU:  Intel Broadwell-DE

                Motherboard model:  Camelback Mountain, or Beverly Cove

                BIOS Version:  AMI Grangeville BIOS 5.011, Tag 18

                 

                Thanks again for your help.

                 

                Chad

                • 5. Re: RAID1 capacity
                  Intel Corporation
                  This message was posted on behalf of Intel Corporation

                  Hello, cscarbro:


                  Thank you for the information provided, we were checking and the support for this type of system would be provided by the distributor or whomever that handed this over to you, why? due to the fact that this is for design purposes (pre-production) the support is going to be with them.


                  Chances are that this is not working properly because the software is used for production systems and this is another platform.

                  Additionally, for design questions or support, you can get support here: http://www.intel.com/content/www/us/en/embedded/embedded-design-center.html


                  About the amout of data used, it could be more with software RAIDs that hardware RAIDs, just to clarify on that matter.

                  Hope this information is useful for you, if any additional questions or inquiries are present, feel free to contact us back.

                  Regards,
                  Esteban C

                  • 6. Re: RAID1 capacity
                    cscarbro

                    Hello, Esteban,


                    I found this other thread in the Intel community which sounds very similar to my situation.  Do you think the answer provided there might be the answer to my question?


                    The thread is here:

                    https://communities.intel.com/thread/42410?start=0&tstart=0


                    Their answer is basically that 5% of any SW RAID array is reserved for root processes and/or rescue actions.  Does this make sense to you?


                    Thanks again,

                    Chad

                    • 7. Re: RAID1 capacity
                      Intel Corporation
                      This message was posted on behalf of Intel Corporation

                      Hello, cscarbro:

                      Thank you for your answer on this, acutually yes, that 5% is required to get everything to work properly.

                      Good catch on that old thread.

                      If any additional questions or inquiries are present, feel free to contact us back.

                      Regards,
                      Esteban C