Storage arrays: Avoiding integration problems
20 Oct 2005 | SearchStorage.com
Selecting a storage array is certainly an important milestone in any data center upgrade or expansion plan, but acquisition is only part of the process -- you'll still need to take possession of the new system, get it installed in the data center, then provision the system and migrate any affected data. Try the storage array in your lab environment and identify any glaring compatibility or interoperability issues before purchase. Even when test results are positive, getting a new storage array up and running can sometimes become a daunting challenge for even the most seasoned IT manager. However, some forward thinking can make the installation as painless as possible:
Look ahead to necessary facilities changes. IT managers often forget that their new storage array will actually need a suitable place in the data center. This usually involves more than just "shuffling equipment". The new array must actually fit through the door, and have a spot in the data center that provides adequate power and network connectivity. An additional storage array may demand more cooling in the data center. It's vital to prepare a spot for the new array and implement any facilities changes needed to accommodate the system in advance. Changes may involve reinforcing the elevated floor where the array will be located, updating electrical service (e.g., more plugs or higher amperage), or adding ventilation for supplemental cooling (if necessary). Communicate with the array vendor and leverage their experience to ensure that you're fully prepared for a successful installation.
Don't forget about related IT tasks. Any infrastructure that supports your storage systems must also be scaled or reconfigured to accommodate the new storage array. "As capacities grow, the time to backup increases," says James Dobson, systems architect at Dartmouth College. He notes that a new storage array may require additional backup equipment (e.g., tape libraries) to protect the system with a reasonable backup window, RPO and RTO. Dobson also points to underpowered UPS (uninterruptible power supply) equipment as a common oversight, suggesting that a UPS may need to be replaced or upsized to support another storage array.
Anticipate the day of installation. Users and analysts all agree that advance planning is the key to a successful installation. It's important to communicate with your deployment team and understand who is responsible for each phase of the installation process. The trickiest part of this process is to recognize the role of your vendor, and have a clear picture of their participation. Know every step of the installation process -- including who uncrates the unit and moves it into place, who connects it, who powers it up and tests it, and who verifies its operational status. "One of the biggest errors is 'assumptions'," Schulz says. "You 'assume' that the vendor was going to include something, but the vendor 'assumed' that you were going to take care of something." This lapse of communication can easily cripple an installation. Schulz says that both you and the vendor must understand and agree on the meaning of "installed".
Don't oversimplify the provisioning and configuration. It's important to establish an array configuration that fits your environment. Dobson sees many users over-simplifying the configuration of their large arrays, often leading to unexpected problems. "You make one big volume out of an entire array, and then you find afterwards that the operating system (OS) may not support something that large," he says. Such over-simplifications often result in unusable space, wasting space on active drives, RAID drives and hot spares. Getting the configuration right at the start can reduce the disruptions involved in reconfiguring the array later. "Reconfigurations tend to affect the entire array," Dobson says, resulting in profound implications for the users sharing the array. Arrays also require an investment of effort once they're installed and configured. For example, corporate data must often be migrated to the new array, and it may take time before the array's value is fully realized. "Features like replication can be extremely difficult and time consuming to integrate," Foskett says. It may take time and effort to see the benefits promised by the vendor.
Make long-term plans for service. Consider how any new array acquisition will be maintained once it's installed. Know when to call for service, what you can expect from the service organization, and whether service is coming from the vendor directly or from a third-party service provider (some enterprises have serious concerns about third-party service providers working in their data center). Understand what knowledge your internal IT staff should master, and take the steps to provide them with that knowledge. James S. Tarala, CIO/CTO of Schenck Business Solutions, says that it's a bad idea to let the vendor "own" their equipment once it's bought. "Anything we bring in, I expect to have ownership of," he says. Tarala's array vendor worked with his staff, provided training on management utilities, helped with flash upgrades and performed setup tasks. Go to the next part of this article: Storage arrays: What is the best storage array?
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