The Microsoft MPIO architecture provides hardware and software vendors with a means of creating Microsoft MPIO solutions that work effectively with the Windows Server operating system to provide organizations with reliable I/O path support on Windows 2000 Server, Windows Server 2003 / 2008, and Windows Storage Server 2003 platforms.
Organizations of all sizes can now benefit from increasingly flexible multipathing solutions in Windows environments. Once only affordable by enterprise organizations (who generally purchased end-to-end storage solutions from a single vendor), high availability and high performance multipathing storage solutions are increasingly in demand from midsized organizations whose storage network configurations routinely consist of multi-vendor devices.
By providing a single interface through which vendors each develop their own device-specific multipathing solutions, the Microsoft MPIO architecture not only ensures compatibility within current and future Windows platforms, but also prevents the multi-vendor device incompatibilities that have plagued previous multipathing solutions. These advantages bring multipathing solutions to midsized and small businesses, and offer enterprise customers greater flexibility in the storage solutions they adopt, allowing them to maintain existing enterprise solutions while also adding less expensive storage solutions to support storage management scenarios.
1. What is multipathing?
2. How is clustering different from multipathing solutions?
3. Does Microsoft MPIO work with clustered solutions?
4. Does Microsoft MPIO work with iSCSI?
5. Are there any Microsoft MPIO-specific newsgroups?
6. Will Microsoft provide the generic Device Specific Module (DSM) for iSCSI? If yes, will it support load balancing or failover mode only?
7. Will using the Microsoft MPIO multipath solution improve performance compared to vendor-specific multipath solutions?
8. Does Microsoft MPIO allow multiple Device Specific Modules (DSMs) to run simultaneously on the same server?
9. Are there any plans to release an "Industry Standard" Device Specific Module (DSM) for Fibre Channel?
10. As a storage vendor, why would my customer care if my multipath solution is based on Microsoft MPIO or not?
11. Which Windows OS versions can be supported by storage vendors with Microsoft MPIO?
12. Which processor architectures can be supported with Microsoft MPIO?
1. Multipathing solutions use redundant physical path components–adapters, cables, and switches–to create logical "paths" between the server and the storage device. In the event that one or more of these components fails, causing the path to fail, multipathing logic uses an alternate path for I/O so that applications can still access their data.
2. Although both multipathing and clustering result in high availability and improved performance, they are not equivalent concepts. While clustering provides high application availability and can be implemented using a multipathing solution, multipathing provides high storage availability and does not require a clustering solution. Clustering is the use of multiple computers, interconnects, and storage devices that work together to provide users with high application availability from what looks like a single system. Multipathing, as stated in the previous question, is the redundancy of the storage network components (the cabling, adapters, and switches) to provide users with high storage availability.
3. The Microsoft MPIO Device Specific Module (DSM) is responsible for all aspects of cluster interoperability. Users must find out the level of support from the provider of the Microsoft MPIO solution.
4. Yes, Microsoft MPIO is fully compatible with the Microsoft iSCSI Initiator.
5. Yes. Go to news://msnews.microsoft.com/microsoft.public.storage, the public newsgroup that you can use for Microsoft MPIO-related questions.
6. Yes, the Microsoft iSCSI Initiator v2.0 released in June 2005 includes an industry-standard Microsoft MPIO DSM. Additionally, Microsoft provides the source code for this DSM to its Microsoft MPIO partners as part of the Microsoft MPIO Driver Development Kit (DDK). Partners are free to use this source code as a base for developing their own MPIO DSM.
7. Microsoft MPIO was designed to be a high-performance platform, but performance depends on the actual implementation of the Device Specific Module (DSM), not Microsoft MPIO.
8. Yes. Microsoft MPIO enables coexistence for multiple vendors' solutions, which many customers consolidating servers and storage want.
9. Yes. The Microsoft industry-standard DSM for Fibre Channel is planned for inclusion in Microsoft Windows Server code-named Longhorn.
10. Customers want Microsoft MPIO-based solutions for both reliability and supportability reasons. Microsoft MPIO was designed specifically to work with the Microsoft Windows operating system, and Microsoft MPIO solutions are tested and qualified by Microsoft for compatibility and reliability with Windows. Many customers do require that Microsoft support their storage solutions, and Microsoft MPIO is no exception. With a Microsoft MPIO-based solution, customers will be supported by Microsoft should they experience a problem. For non-Microsoft MPIO solutions, Microsoft support is limited to a "best effort" type of support only, and customers will be asked to contact their MPIO solution provider for assistance.
11. Windows Server 2000, Windows Server 2003 / 2008 and Windows Server 2003 R2 / 2008
