Белая книга для Cisco Cisco MDS 9000 NX-OS Software Release 4.1
White Paper
© 2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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The Virtual Machine Aware SAN
What You Will Learn
Virtualization of the data center, which includes servers, storage, and networks, has addressed
some of the challenges related to consolidation, space constraints, demand for high power, and
cooling requirements. End-to-end virtualization helps increase efficiency and reduces overall total
cost of ownership (TCO). Virtual machines make it possible to run multiple applications and
operating systems in a single machine. However, the proliferation of virtual machines introduces
new challenges for the SAN, including challenges related to loss of visibility, security, traffic
isolation for applications, quality of service (QoS), performance monitoring, and management
complexity.
The Cisco
®
MDS 9000 Family provides VN-Link Storage Services to support the Data Center 3.0
vision by enabling IT departments to dynamically respond to changing business demands,
providing fabric scalability and performance, performance monitoring and trending, QoS, Virtual
SANs (VSANs) for fault isolation, and mobility for virtual machines.
This document describes the innovative approach introduced by the Cisco MDS 9000 Family to
support an end-to-end virtualized SAN environment that is flexible, secure, scalable, and mobile.
Challenges of the Virtualized Environment
Server virtualization technologies enable the consolidation of numerous application servers on a
much smaller number of physical servers running a hypervisor, a specialized operating system
capable of hosting multiple guest system images. While this solution dramatically reduces the
administrative steps required to deploy and administer each individual application server, it is very
demanding for the network infrastructure.
Challenges for the network infrastructure include:
●
Change of communication patterns from a many-to-one model to a many-to-few (mesh)
model
●
Unpredictable traffic generated by the dynamic movement of virtual machines across
physical servers
●
Rapid deployment of virtual machines without complex management procedures and
without affecting security
This document analyzes these challenges in detail.
Complex Communication Patterns
The fundamental building block of the virtualized data center is not the individual server, but a
cluster of servers, possibly sharing access to a large amount of storage. The most commonly
deployed hypervisor typically uses a cluster of 32 servers.