Question: What are the advantages of storing a virtual machine on a Server Message Block file share?
Answer: The ability to store virtual machines (VMs) on an SMB file share was a feature Microsoft introduced in Windows Server 2012 and Hyper-V 3.0. Prior to this release, organizations had a few different options for storing VMs, including direct-attached storage, SCSI pass-through disks, Fibre Channel storage area network and iSCSI storage.
More on Hyper-V SMB file shares
Fault tolerance improvements, more speed features of SMB 3.0
SMB 3.0 development on hold until Windows Server 2012
SMB 2.2 in Windows Server 8 gives Microsoft cloud a boost
In the case of a standalone Hyper-V server, being able to move the VM to SMB storage means not having to provision the host server with local storage for VM use. VMs are demanding in terms of disk I/O and a storage array is almost always required for adequate VM performance. Organizations might be able to avoid the expense of a dedicated storage array if they already have a high-performance file server with enough free space to accommodate the VM.
In the case of a failover cluster, previous versions required the use of a Cluster Shared Volume (CSV). This type of shared storage was expensive to implement and often put Hyper-V clusters financially out of reach for smaller organizations. In Hyper-V 3.0, SMB storage can be used as an alternative to a CSV.
It is worth noting that although Hyper-V supports placing VMs on SMB storage, the file server must be running Windows Server 2012 with the SMB 3.0 protocol (previously known as SMB 2.2). Furthermore, the use of SMB storage for VMs is primarily geared toward smaller organizations. Bandwidth limitations make the use of SMB storage impractical for large numbers of VMs.
This was first published in December 2012