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Hyper-V Storage Allocation RRS feed

  • Question

  • Hi

    I can't seem to get my head around the storage allocation of DPM.

    The initial backup is put in the "Replica Volume" am I pretty sure of. When the job then run the next "Express full backup", from what I have found, it only takes data that has been changed since the initial backup. but is this delta data put in the "Replica Volume" or "Recovery Point Volume"?

    I have set up backup of some VM's in our cluster, and most fails with not having enough space, but I have set all backup to auto grow, so why dosn't it just grow the volumes? And is it both the "Replica Volume" and "Recovery Point Volume" that it can grow, or only one of them?

    The last question, isn't that much about allocation, but, After the initial replica has been created, delta point is being created, but if I have 2 days retension, what happens the third day, is the first delta commited to the replica and therefor requires space in the "Replica Volume" or how does that work?

    Thanks a lot, in advance!

    Regards Lars

    Monday, October 26, 2015 10:37 AM

Answers

  • Hi Lars,

    After the initial replica has been created and put in the Replica Volume, only block-level changes will be transferred between your Hyper-V host and the DPM-server. How often this transfer occurs is based on how often you have chosen to create a recovery point in DPM. The data transferred will be put in the Recovery Point Volume.

    When you have enabled the auto-grow feature, DPM can grow both the replica and recovery point volume by 10GB or 25% whichever is higher. So you may get the error the initial replica or/and recovery point volume has not been allocated enough storage when you configure the protection and the auto-grow is not enough. (Auto-grow can only occur every 15 minutes). The following link is to the TechNet-article about how DPM allocates storage for different workloads: Allocating Space for Protection Groups

    For your last question: Every night at midnight DPM will lunch powershell script called pruneshadowcopiesdpm that will update the replica with the earliest recovery point located in the recovery point volume of the DPM server, but this happens only if the retention time is expired. In you case the night between day 2 and 3.

    I hope this answers your questions!

    Kind Regards
    Markus Eliasson

    Monday, October 26, 2015 3:19 PM

All replies

  • Hi Lars,

    After the initial replica has been created and put in the Replica Volume, only block-level changes will be transferred between your Hyper-V host and the DPM-server. How often this transfer occurs is based on how often you have chosen to create a recovery point in DPM. The data transferred will be put in the Recovery Point Volume.

    When you have enabled the auto-grow feature, DPM can grow both the replica and recovery point volume by 10GB or 25% whichever is higher. So you may get the error the initial replica or/and recovery point volume has not been allocated enough storage when you configure the protection and the auto-grow is not enough. (Auto-grow can only occur every 15 minutes). The following link is to the TechNet-article about how DPM allocates storage for different workloads: Allocating Space for Protection Groups

    For your last question: Every night at midnight DPM will lunch powershell script called pruneshadowcopiesdpm that will update the replica with the earliest recovery point located in the recovery point volume of the DPM server, but this happens only if the retention time is expired. In you case the night between day 2 and 3.

    I hope this answers your questions!

    Kind Regards
    Markus Eliasson

    Monday, October 26, 2015 3:19 PM
  • Tuesday, October 27, 2015 12:39 PM
  • Hi

    Thank you for the detailed information!

    @EugeneLeitan: I will take a look at the video.

    Regards Lars

    Thursday, October 29, 2015 11:00 AM