How do you buy a storage system? Not too many years ago you probably bought a fully configured, storage system, and depreciated it over 3 years. You only needed less than a third of the capacity when you bought it, but capacity was cheap and you figured that your workload would increase and you would fill it up over the next three years. Even though you knew that the cost of storage capacity erodes quickly over time, you bought more than you needed at current prices because it would be too disruptive to add the capacity in increments. Besides the vendor gave you a great deal, and you would quickly fill it up anyway.
At the end of three years you found that the capacity of a disk is now four times what it was three years ago for the same price. However, to use these disks you need to upgrade to the next generation storage system with higher speed Fibre Channel ports, larger cache, new replication functions, and more than double the number of disks. Buying a fully configured system for your next round is out of the question. So this time you, decide to take a more measured approach. You buy only the control unit and enough capacity to cover the next year’s growth, with the thought that you can add capacity as you need it at a lower cost in the future. A year later when you go to add the additional capacity, you find you need to upgrade your control unit with more ports and cache as well as more storage frames to hold the additional capacity. You also find that the cost per GB is cheaper but it comes on fewer disks. Since you need a certain number of disks for performance, you buy more capacity than you need. An outage is required to add the new capacity and reconfigure the cache and port assignments. A year later you repeat this again for the next year’s storage growth.
Now at the end of three years, you find that the original control unit and capacity that you bought three years ago are no longer under warranty and you have to start paying maintenance fees which are quite expensive. In fact it is almost cheaper to buy the next generation control unit and the larger capacity disks, than pay maintenance on the old control unit with its three year old disks. But wait, if you swap out the control unit, you also have to swap out the capacity that you just bought over the last two years, since the control unit and disk capacity are bound together. So you either pay the maintenance charges or you give up the depreciation on the upgrades you purchased over the last two years.
You would not have to do this if you could separate the control unit from the storage media and capitalize them separately. With the USP VM, you can buy the latest high function storage control unit without buying any storage media. You can connect it to your existing storage systems and upgrade the functionality of those storage systems with the latest USP storage services like volume virtualization, Dynamic Provisioning (thin provisioning), universal replication, and non-disruptive migration. If you need more capacity you can buy another storage system with the latest large capacity disks and connect it to the USP VM. With Dynamic Provisioning you only need to buy the capacity you need since the new disks can be added to a dynamic storage pool and the I/O will be spread across all the disks in the pool to level out the spindle load. When it comes time to replace the USP VM, you can continue to depreciate the storage system that you bought later by attaching it to the next generation USP V or VM.
The separation of the storage controller from the storage media is the next step in the disaggregation of storage. In the beginning, storage and servers were integrated. When you needed to change a server you also had to change the storage. That problem was solved by separating the server and storage. By separating the storage controller from the media, you now have the choice of mixing and matching controller functions and storage media to provide the best solution for your storage requirements. And with storage virtualization and dynamic provisioning, you only need to buy what you need when you need it with out disruption to your applications.
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