An infrastructure architect is submitting a proposal for a vSAN Cluster.
These are the customer's requirements:
✑ Maximize the amount of usable capacity.
✑ Deduplication and compression will be enabled to help maximize usable capacity.
Which disk group configuration should the architect include in their design?
To maximize the amount of usable capacity in a vSAN cluster with deduplication and compression enabled, the best configuration would involve one disk group with one flash device for cache and six flash devices for capacity. This setup will allow deduplication and compression to be most effective within the single disk group, resulting in a higher deduplication ratio and maximizing usable capacity.
Agreed, A is correct based on the criteria being asked for. Taken from VMware doco "vSAN can eliminate duplicate data blocks within each disk group, but not across disk groups" https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan.doc/GUID-2285B446-46BF-429C-A1E7-BEE276ED40F7.html
A and B are the only two possible answers as DD&C is only available on all flash configuration. I'm gona say A is correct as DD&C is performed per disk group so a single disk group will give a better DD ratio. I'm aware that best practice is always to have more than one disk group, for performance and redundancy (more fault domains) but the question does not mention best practice, only maximizing capacity. The article below does say to use more than one disk group, however it is in relation to performance. https://blogs.vmware.com/virtualblocks/2020/06/18/vsan-design-considerations-deduplication-and-compression/ In my opinion , and based purely on the wording of the question I think that answer A is correct.
I agree with you, A and B are the right but the important point is raion so the larger the disk group is the higher ratio.
B. When you enable deduplication and compression on a vSAN cluster, all disk groups participate in data reduction through deduplication and compression. You can add a capacity disk to a disk group with enabled deduplication and compression. However, for more efficient deduplication and compression, instead of adding capacity disks, create a new disk group to increase cluster storage capacity. https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan.doc/GUID-AA72CA1D-803D-4D1D-87BB-E7D86EC947D2.html
I believe A is correct and if comes in exam i would flip coin between A and B :)
A is correct