• This topic has 2 replies, 1 voice, and was last updated October 23, 2022 by drteam@sgintl.com.

Function question

  • Posting this on behalf of  YoungChul.H

    1. Is there a support direction for redundancy solutions using RDM? (RAC, ASM, VCS … etc)

    2. If I change the redundancy solution using RDM to VMDK format (multi-writer) and create a VPG, can it be consistent?
    Writing occurs in different VMs by VMDK’s share method(I don’t expect)

    3. Can I clone only the disks I want to be attached to the VM? OR Will the corresponding functions be supported in the future?

    4. When the network between main site and DR site is broken, VRAs may not work properly, When the network is normal between the two sites, the VRA is automatically
    Shouldn’t it be normal?

    The client wants to answer the above question. Please answer the questions that Zerto headquarters can provide.

    Hello YoungChul,

    Mike from Zerto here. To answer your questions:

    1. Is there a support direction for redundancy solutions using RDM? (RAC, ASM, VCS … etc) – Please see the following links:

    http://s3.amazonaws.com/zertodownload_docs/Latest/SQLBestPractices.pdf?cb=1567533051

    http://s3.amazonaws.com/zertodownload_docs/Latest/Zerto%20Virtual%20Replication%20Zerto%20Virtual%20Manager%20%28ZVM%29%20-%20vSphere%20Online%20Help/index.html?cb=1567533051#page/AdministratorforZertoVirtualManager%2FManageVPG_VC.10.10.html

    If those are not helpful, please elaborate on what you are looking for.

    2. If I change the redundancy solution using RDM to VMDK format (multi-writer) and create a VPG, can it be consistent?
    Writing occurs in different VMs by VMDK’s share method(I don’t expect) – If you use multiwriter mode, you may run into issues with Failover where the VM does not boot, and the following error is seen:

    Cannot open the disk ‘/vmfs/volumes/……/XXXX.vmdk’ or one of the snapshot disks it depends on.
    Thin/TBZ/Sparse disks cannot be opened in multiwriter mode

    To work around that, you would need to delete the VPG, keeping the recovery disks, and the recovery preseed disks should be changed to a Thick Eager Zero provisioning.
    This can be done with an ESXi command line tool named vmfkstools.

    The needed command, which runs on the ESXi host is:
    vmkfstools –eagerzero /vmfs/volumes/DatastoreName/VMName/VMName.vmdk

    This subject and the remediation method (with vmkfstools) is covered in the following VMware KB:
    https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1035823

    Once completed, please create the VPG with preseeding.

    For a video demonstrating a working clustering setup, where the recovery disks are VMDKs, please see https://zerto.box.com/s/ch100ad617rofrizitv82mwl4l93v2yl

    3. Can I clone only the disks I want to be attached to the VM? OR Will the corresponding functions be supported in the future? – You cannot have Zerto ignore disks in a protected VM outright. What you can do is mark any disks you do not want Zerto to actively replicate as Temp Data. What that does is the disks will be synced to the recovery site, but they will not be actively replicated. For more information, please see the following: https://www.zerto.com/myzerto/knowledge-base/how-to-designate-a-volume-as-a-temp-data-disk/

    4. When the network between main site and DR site is broken, VRAs may not work properly, When the network is normal between the two sites, the VRA is automatically
    Shouldn’t it be normal? – What you described is normal

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