VMware 3V0-23.25 - Advanced VMware Cloud Foundation 9.0 Storage

Windows Server Failover Cluster shared disks require coordinated access to shared block storage. vSAN supports Windows Server Failover Clusters by providing SCSI-3 Persistent Reservation support at the virtual disk level, which allows cluster nodes to arbitrate access to a shared disk resource. One supported approach is to use the vSAN iSCSI Target Service, which presents vSAN-backed LUNs to initiators and can be used for clustered workloads that require shared block access. Another supported approach is to configure a shared virtual disk using a VMware Paravirtual SCSI controller with physical bus sharing. Physical bus sharing allows multiple VMs to access the same shared virtual disk in a WSFC configuration where supported. Raw Device Mapping is not the vSAN ESA-native solution for this requirement. NFS v4.1 is a file datastore protocol, not a WSFC shared block disk mechanism. “LSI SCSI controller per disk” does not satisfy the required shared-disk bus sharing configuration. Reference topics: vSAN Support for Windows Server Failover Clusters, SCSI-3 Persistent Reservations, vSAN iSCSI Target Service, Shared VMDK Configuration.

The architect should highlight that quotas and Access Based Enumeration are configured when creating the vSAN file share, with ABE available for SMB shares. In the vSAN File Service create-share workflow, the General page allows the administrator to choose the protocol and configure protocol-specific options. When SMB is selected, the share can be configured with Access Based Enumeration, which displays only files and folders that the user has permission to access and hides files or folders where the user lacks Read or equivalent permissions. The same create-share workflow also includes Storage space quotas, including a share warning threshold and a share hard quota. Therefore, the design implication is operational: quotas and ABE must be planned and applied at the file-share configuration level for SMB shares that require both controls. Quotas are not limited only to NFS shares, and ABE is not a cluster-level setting. Separate file service servers are also unnecessary because vSAN File Service supports SMB and NFS shares through the same file service architecture. Reference topics: vSAN File Service, Create vSAN File Share, SMB Access Based Enumeration, Storage Space Quotas.

A vSAN Stretched Cluster requires both compute placement control and storage placement control. To place virtual machines in the appropriate site, the administrator must create VM/Host groups for the two sites. This allows DRS to understand which hosts belong to the preferred site and which hosts belong to the secondary site, and it allows VM-to-host affinity rules to be created for initial and ongoing placement. The administrator must also create a storage policy for each site or site placement requirement. vSAN stretched-cluster storage policies control site disaster tolerance and data locality, including whether objects are mirrored across sites or kept on the preferred or secondary site. VM folders do not control runtime or storage placement. A VM/Host group “across the two sites” is not correct because site separation must be explicitly modeled. Simply placing a VM into a DRS group is not enough unless the site groups and policies already exist. Reference topics: vSAN Stretched Cluster Design Considerations, DRS Host Groups, VM Groups, VM-Host Rules, vSAN Storage Policy Site Locality.