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SC Series snapshots and Hyper-V
27 Dell EMC SC Series: Microsoft Hyper-V Best Practices | CML1009
3 SC Series snapshots and Hyper-V
SC Series snapshots are space-efficient, meaning they consist of pointers to frozen data blocks, and
therefore consume no additional space unless, for example, a View Volume is created from a snapshot,
mapped to a host and new data is written.
SC Series snapshots can be taken of volumes mapped as LUNs to a Hyper-V environment regardless of
content. This applies to boot-from-SAN volumes, data volumes, cluster shared volumes (CSV), pass-through
disks, in-guest iSCSI volumes, and vFC volumes. These volumes along with their snapshot histories can also
be replicated to other SC Series arrays for DR or archive purposes.
SC Series snapshots allow administrators to do the following in Hyper-V environments:
• Recover servers to a crash-consistent state, including Hyper-V hosts and guest VM workloads.
• Provision lab or isolated test environments using View Volumes.
• Provision new servers using gold images.
Unless the server is powered off at the time the snapshot is taken or put into a consistent state by Replay
Manager or some other volume shadow copy (VSS) aware application, SC Series snapshots are considered
crash-consistent. When recovering a server using a crash consistent snapshot, it is like having the server
recover from a power outage at that point in time. In most cases, servers and applications are resilient
enough to recover to a crash consistent state without any issues, whether the cause is an unexpected power
outage, or the server is being recovered to a previous point in time. An exception to this is when the Hyper-V
environment hosts a transactional workload such as Microsoft Exchange or SQL Server. With transactional
workloads, the risk of data corruption or loss is higher when attempting to recover to a crash consistent state.
Some examples for how to configure and use SC Series snapshots for Hyper-V environment are provided
below.
3.1 SC Series Replay Manager support for Hyper-V
Replay Manager can be used to obtain application-consistent backups (Replays) of Hyper-V guest VMs. The
Hyper-V extension for Replay Manager leverages VSS to ensure that a guest VM is in a consistent state
before a snapshot is taken. Replay Manager also includes extensions to protect Microsoft Exchange, SQL
Server and VMware VMs.
To learn more about Replay Manager for Hyper-V, see the
Dell EMC SC Series Replay Manager best
practices guide and demo video. Many other Replay Manager documents and videos are found at SC Series
technical documents and videos.
3.2 Use SC Series snapshots to recover guest VMs
A Hyper-V guest VM can be recovered to a previous point in time by using crash-consistent SC Series
snapshots of the underlying host volume containing the virtual hard disk. Snapshots can also be used to
create copies of VMs in an isolated environment at the same or a different location when volume replication
between SC Series arrays is used. This section provides guidance and best practices for several different
recovery options using snapshots.