How long does an organization keep a storage system? That depends on a few things. For disk systems, there are several driving factors:
• The length of the warranty period and the cost of a service contract after the warranty period.
• The depreciation period on the system.
These factors usually lead organizations to plan on four or five years before replacing their disk storage system.
For tape systems that use LTO technology, IT generally looks at how long new tape drives can be purchased to read their existing tapes. Each new generation of LTO tape drive can read tapes created on the two previous generations. The period for replacement of tapes (meaning migration of the data on those tapes) to a new generation is based on how long it takes for LTO tape generations to be released. It usually takes around seven years to get to the generation that cannot read the previous two generations.
When I speak with contemporaries of mine in other technology disciplines and reflect on the limited lifespans of storage systems, they find it hard to believe how short the lifespan is for storage systems. They usually say that, with the amount of investment made, a storage system should be kept for at least 10 years.
They understand the shorter lifespan better when I explain the pace that storage technology changes and the benefits from more frequent updates. These include:
• Greater efficiency in power, space, and cooling with new, higher capacity devices
• Improved performance with system support solid state technology
• New warranty periods for new storage systems rather than relatively expensive maintenance contracts for storage systems past their warranty period
• Improved reliability for new systems.
The discussion then shifts to how difficult it is to move to a new storage system, mainly because of data migration. Some storage systems automatically migrate data from an older storage system, especially if the migration is between different generations of the same system. If the migration is not transparent and automatic, it costs more to move to another generation of disk storage.
It gets more complicated when switching to another vendor or a different architecture from the same vendor. The new system may require administrators to provision and manage the storage differently than the old system. Administrators must understand the differences, learn new tools or administrative interfaces, and set up new procedures to monitor and respond to issues. These add to the acquisition cost when calculating TCO (Total Cost of Ownership) and pose a potential risk before being effectively implemented.
IT teams would obviously like a longer lifespan for storage systems, but changes in technology make tradeoffs skewed towards replacements at regular intervals. And as technology progresses, there may be a point that longer lifespan systems have greater economic advantages than what we have now.
