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vStart 1000m for Enterprise Virtualization using Hyper-V – Reference Architecture
Dell Inc. 23
6.6.12.1 Jumbo Frames
In the vStart configuration, Jumbo Frames are enabled for all devices of the iSCSI SAN fabric. This
includes the server network interface ports, the network switch interfaces, and the Compellent
interfaces.
6.6.12.2 Thin Provisioning
Particularly in Virtualization environments, thin provisioning is a common practice. This allows for
efficient use of the available storage capacity. The LUN and corresponding CSV may grow as needed,
typically in an automated fashion to ensure availability of the LUN (auto-grow). However, as storage
becomes over-provisioned in this scenario, very careful management and capacity planning is critical.
Dell Compellent Thin Provisioning delivers the highest enterprise storage utilization possible by
eliminating pre-allocated but unused capacity. The software, Dynamic Capacity, completely separates
allocation from utilization, enabling users to provision any size volume upfront yet only consume disk
space when data is written. Thin Write technology assesses the incoming payload and designates
capacity for each write on demand, leaving unused disk space in the storage pool for other servers and
applications.
6.6.12.3 Volume Cloning
Compellent offers the Remote Instant Replay
TM
feature to support volume cloning. Remote Instant
Replay leverages space-efficient snapshots between local and remote sites for cost-effective disaster
recovery and business continuity. Following initial site synchronization, only incremental changes in
enterprise data need to be replicated, minimizing capacity requirements and speeding recovery.
Known as Thin Replication, this unique approach enables network storage administrators to choose
between Fibre Channel and native IP connectivity for data transfer.
Volume Cloning is another common practice in Virtualization environments. This can be used for both
Host and VM volumes, dramatically increasing Host installation times and VM provisioning times.
6.6.12.4 Volume Snapshots
SAN Volume snapshots are a common method of providing a point-in-time, instantaneous backup of a
SAN Volume or LUN. These snapshots are typically block-level and only utilize storage capacity as
blocks change on the originating volume. Some SANs provide tight integration with Hyper-V, integrating
both the Hyper-V Microsoft Volume Shadow Copy Service (VSS) Writer on Hosts and Volume Snapshots
on the SAN. This integration provides a comprehensive and high-performing backup and recovery
solution.
Dell Compellent Replay Manager is powerful snapshot-consistency software that integrates with VSS to
ensure the integrity of Exchange Server, SQL Server and Hyper-V data. By initiating snapshots when the
I/O is quiesced, Replay Manager provides time-consistent snapshots even if the application or virtual
machine (VM) is running during the process. The application-aware technology leverages Data Instant
Replay, which creates space-efficient snapshots for recovery of most volumes to a server in less than
10 seconds.