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Highly available storage virtualization

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Article from ADMIN 46/2018

By Roland Döllinger

Implementing highly available SAN data storage virtualization.

To ensure that companies have permanent access to their own data, many technologies for data storage and management have been established over the years. One solution is storage virtualization, which is a useful approach for coping with massive data growth. In this article, I provide an overview of basic technologies and explain how to implement highly available storage area network (SAN) scenarios.

Data Storage Virtualization

Much like server virtualization, data storage virtualization promises better utilization of resources, simplified central management, and increased data availability. Various technical approaches come together under the storage virtualization umbrella. Each adds a logical – virtual – layer to the storage environment that abstracts servers and applications from the actual physical storage, allowing this storage to be combined into larger areas or pools.

The server operating system itself offers a simple type of storage virtualization by grouping several individual physical hard drives, or logical unit numbers (LUNs), into volume groups and creating logical volumes or devices from them. These are then addressed by the OS as a single virtual hard drive. This type of storage virtualization is used very frequently, especially in Unix-style operating systems that come standard with a Logical Volume Manager. For higher data availability, these volume groups can also be mirrored in RAID 1, which – assuming the corresponding SAN infrastructure is in place – enables synchronous databases at two different locations. However, centralized management, which allows all servers and the associated storage resources to be administered and monitored in one place, is not typically available.