By David Vellante and Dave Simpson
Managing SANs has never been a cakewalk, but it's become even more difficult in the context of virtual servers, particularly environments with large, heterogeneous SANs and a lot of virtual machines (VMs).
SAN managers need deeper visibility into their storage networks and virtual/physical server infrastructure, and a handful of vendors have tools that provide cross-domain monitoring and analysis tools for those environments. It's a product category that the Taneja Group research and consulting firm refers to as virtual infrastructure optimization (VIO).
From a storage-centric perspective, Dave Bartoletti, a senior analyst with the Taneja Group, points to products such as Akorri's BalancePoint, NetApp's SANscreen, and Virtual Instruments' NetWisdom as examples of VIO tools. (Dell also has VIO software, called SAN HeadQuarters, or SANHQ, but it only works with Dell's iSCSI arrays. In addition, Dell resells Virtual Instruments' NetWisdom.)
Based on conversations with users that have deployed VIO tools, Bartoletti says that the primary benefits and use cases are:
- Faster problem diagnosis (e.g., detecting the source of bottlenecks)
- Real-time queue monitoring for improved performance
- Faster detection of failures (particularly on SAN-based devices)
- Tracking configuration changes (including firmware incompatibilities)
- Improving storage tiering (based on performance statistics)
- Optimizing consolidation ratios (e.g., how many virtual machines you can add without incurring performance penalties)
"Lack of visibility into the SAN infrastructure and virtualized environment is becoming more acute as IT organizations move mission-critical applications into the virtual environment, because those applications have more demanding performance requirements," says Bartoletti. He also notes that VIO tools give storage, server and network teams a common view of the entire infrastructure, which enables them to accurately evaluate the environment without finger-pointing.
Tools for managing virtual servers and SANs encompass all aspects of virtual infrastructure management, including troubleshooting, capacity planning, performance optimization, and service-level management. As such, they provide an alternative to device/vendor-specific "element managers."
The following case studies illustrate the challenges associated with managing and monitoring SANs in virtual server environments and looks at how users solved those challenges – in one case with management tools from Virtual Instruments and NetApp, and in the other case with Akorri's BalancePoint software. –Dave Simpson