Which two conditions would cause this error to occur? (Choose two

An administrator is configuring Storage DRS in their environment. The Datastore cluster is composed of 4 VMFS3 volumes and 9 VMFS5 volumes. Storage DRS has been enabled, but is showing as disabled on several virtual machine disks in the datastore cluster.

Which two conditions would cause this error to occur? (Choose two.)

A.
The virtual machine is stored on a VMFS 3 volume.

B.
One or more virtual machines have Persistent disks.

C.
The virtual machine is stored on a NFS datastore.

D.
The virtual machine is stored on a datastore with a 2mb block size.

10 Comments on “Which two conditions would cause this error to occur? (Choose two

  1. mike says:

    question never states that the VMs were stored on an NFS datastore, all VMs are in VMFS datastores so C is not correct. The answers are correct

    1. karloce says:

      Here you go:
      http://www.vmware.com/files/pdf/techpaper/vsphere-storage-drs-interoperability.pdf

      When applying the default affinity rule inside a datastore cluster, all virtual machine files detected by Storage DRS will be migrated to another datastore if a migration recommendation is applied. Persistent state files (“.psf”)introduced by vSphere Replication are not detected by Storage DRS and are not migrated, but rather deleted, when a virtual machine is moved.

  2. Ken says:

    This question is crap.

    Here is vmware’s official troubleshooting document for when storage DRS is showing as disabled on a virtual disk:
    http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.troubleshooting.doc_50%2FGUID-B749AAA0-7B67-4A79-BEDC-395DFEC9FC60.html&resultof=%22%73%74%6f%72%61%67%65%22%20%22%73%74%6f%72%61%67%22%20%22%64%72%73%22%20%22%64%72%22%20

    None of the answers given are in the above document.

    This blog states that you can place VMFS 3 and 5 in the same datastore cluster, but it is not recommended.
    http://blogs.vmware.com/vsphere/2011/07/vsphere-50-storage-features-part-5-storage-drs-initial-placement.html
    So A might be correct. The key word is might. Nowhere does vSphere state that mixed VMFS versions will cause storage DRS issues.

    B is not correct. Persistent mode disks are actually a requirement for Storage vMotion. So the fact the VMs have persistent disks is great.
    http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.vcenterhost.doc_50%2FGUID-A16BA123-403C-4D13-A581-DC4062E11165.html&resultof=%22%73%74%6f%72%61%67%65%22%20%22%73%74%6f%72%61%67%22%20%22%76%6d%6f%74%69%6f%6e%22%20

    The above blog also states that VMFS and NFS datastores cannot be mixed in the same datastore cluster. Which is confirmed here:
    http://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.resmgmt.doc%2FGUID-34A10B42-C79E-491C-A5AA-99E3B5FA2278.html
    In other words, you cannot create a datastore cluster with mixed VMFS and NFS datastores. vSphere wont let you. Since the question specifically states that there are only VMFS datastores in the cluster, it would be impossible for a VM to be on a NFS datastore. C cannot be correct.

    The fact that the datastore has a 2mb block size is meaningless. neither storage vMotion, storage DRS, or datastore clustering have any block size requirements. You might be able to infer that this is VMFS 3, but then again, if the datastore had been upgraded to 5, the old block size if retained. So the datastore could be either VMFS 3 or 5. D is not correct.

  3. nadeemka2000 says:

    Below is what I found.

    Answer A

    VMware vSphere (pre-5.0) Hosts Storage DRS does not support vSphere (pre-5.0) hosts connected to a datastore in a datastore cluster. If older versions of vSphere or VMware® ESX®/VMware ESXi hosts are attached to a VMware vSphere® VMFS3 datastore
    in a datastore cluster, Storage DRS load balancing will be disabled. No migration recommendations will be made until all hosts in the datastore cluster are vSphere 5.0 hosts. VMware does not support vSphere (pre-5.0) hosts connected to Storage DRS–enabled datastores. 

    Answer B

    If the disk is an independent disk, Storage DRS is disabled, except in the case of relocation or clone placement.
    Independent-Persistent disks or independent-non persistent disks

  4. Mark says:

    What a crappy question. I’ve been wrestling with this one.

    Take the NFS answer for example:
    – sDRS shows as disabled on several VMs on THE datastore cluster (thus referring to the cluster containing ONLY VMFS)
    – Which condition could cause this error (not necessarily referring to these particular machines anymore, thus no longer discounting NFS as an answer)

    What do I know?
    – NFS won’t work
    – Independent disks won’t work

    So do they mean Independent-Persistent?
    karloce makes a point, but the document clearly states the machine is still moved, the psf-file is simply deleted.

    nadeemka makes a great point. What if there are pre-vS5 hosts? They won’t know what to do with datastore clusters, they’ll treat every datastore as a separate entity. It would seem logical that vSphere 5 would – for backwards compatibility – disable any VM on datastores with machines owned by vSphere 4 an earlier. Which makes VMFS3 a good answer.

    Block sizes slow the migration down, but are no hindrance.

    So technically, if we take the question out of its context, the only two correct answers are A & C.

    If we discount NFS because we’re assuming the question pertains to the scenario above it, rather than a general query, then A & B are the most likely candidates.

    I don’t know, I think I’d choose A & C, then berate them in a comment, hoping they’d read it.


Leave a Reply

Your email address will not be published. Required fields are marked *