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What you will learn: Software-defined storage can help to make storage more flexible and agile, and provide route management to make the best use of network and fabric connections between physical storage devices and servers. However, unless IT pros conduct a steady campaign of storage infrastructure management, environments can still be prone to failure.
The hype around software-defined storage may leave you with a sense that the technology reinvents storage from the ground up, eliminating the need for personnel with expertise in storage hardware infrastructure altogether. The truth is quite different.
Good software-defined storage (SDS) technology may well provide a means to make storage more flexible and agile, so that virtual storage volumes can be created on the fly, associated readily with workloads, and moved or transitioned from server to server together with virtual machines. Moreover, SDS may enable you to associate value-added services with virtual storage volumes -- services that may include mirroring, replication, thin provisioning and deduplication/compression, to name a few -- thus making the storage application a more customized fit to workload requirements. In addition, good SDS technology should provide route management and interconnect load balancing to make the best use of network and fabric connections between physical storage devices and servers that host either (or both) physical workload or virtualized guest machines.
Whether this is called collectively intelligent services management, the agile delivery and management of service-customized volumes or some other airy description by pundits, the simple truth is that SDS does only part of the job of storage management: the management of the storage application. It does not manage storage hardware or plumbing at all.
Managing the physical storage infrastructure, what used to be called storage resource management (SRM) is a must-have if SDS/storage virtualization/Storage as a Service/storage clouds/storage hypervisor technology is to deliver its promised value in a reliable way. Yet, it is seldom discussed or even considered in storage technology acquisitions. Surveys repeatedly reveal that storage management rarely makes the "top 10 list" of features and functions users consider when making a product choice. Vendors console consumers with promises that excellent service, leveraging the "phone home" capabilities of products, is all the storage management functionality anyone needs. Empirical data suggests otherwise.
Recent research published by the University of Chicago covering failures in close to 40,000 storage systems reveals that a considerable amount of downtime accrues annually due to disk failures, interconnect failures and storage protocol failures -- events that might have been preventable with proactive monitoring and management. And case-based accounts, including a recent lengthy shutdown of IT services in the Commonwealth of Virginia (owing to an EMC array failure, compounded by a service engineer's error) show that phone home may not be an adequate substitute to ongoing monitoring and proactive management.
It could be argued that all the hoopla around SDS and its precursors actually points to the proverbial "elephant in the room" -- a lack of infrastructure management, which leads to unacceptable levels of downtime and labor costs that track with or exceed other total cost of ownership categories in storage. The solution is to either adopt an open management standard, such as Amazon Web Services RESTful management, and tell your vendors that you won't buy their rigs if they don't support this standard; or to buy and deploy one of the several effective proprietary management systems for storage, again telling vendors that you have made the product a standard for your company and that they must support the SRM package if they want to put arrays in your infrastructure.
The list of available SRM tools is quite large. Excellent products can be had at an affordable price. My personal favorites include Storage Manager (formerly Storage Profiler, now from SolarWinds) and VirtualWisdom from Virtual Instruments. CA Technologies, IBM, Symantec and others also sport fine products. Without hardware and plumbing management, storage virtualization is a lot like plastic surgery: mom and dad may look prettier, but their offspring might not fit the mold.