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  • 1.  Shared VMDK - multi-writer

    Posted Jun 08, 2021 06:41 AM

    Hello , hope you are all well.

    I have a question maybe you can help me.  Me colleges from windows administration team want a one shred disk between two VMs on which is running SharePoint . So I think to add one vmdk with enabled multi-writer flag on those VMs and they can use on cluster shared volume to set up access . Will this setup work ? 

    For backup they won't use snapshot and for the VMs there are affinity rule to separate them from running on the same host,



  • 2.  RE: Shared VMDK - multi-writer

    Posted Jun 08, 2021 05:41 PM

    You should not turn on the multi-writer option. VMware highly recommends against this. If you want to cluster disks then you need to put them on a SCSI controller where the SCSI Bus Sharing is set to Physical. I like to put clustered disks on their own SCSI controller for ease of administration/organization. Do this on all VMs that will be sharing the disk. Also, make the disk the same SCSI ID on each VM. Depending on your storage (data store versus vSAN or VVol) you may need to thick provision the disk as well. 



  • 3.  RE: Shared VMDK - multi-writer

    Posted Jun 09, 2021 07:29 AM

    hello pdirmann01 , thanks for replay.

    yes , I will add a new SCSI controler , type VMware Paravirtula, SCSI bus sharing :Phisical , and shared disk with multi-writer option , type Thick Provision Eager Zeroed and Disk mode : Independed Persistent.

    this setup should work and be stable.



  • 4.  RE: Shared VMDK - multi-writer

    Posted Jun 09, 2021 05:53 PM

    You typically do not need and should not use multi-writer. See references below. Perhaps, your circumstances require it.

    https://kb.vmware.com/s/article/2121181

    https://blogs.vmware.com/apps/2019/05/wsfc-on-vsphere.html