Data Migration Strategies

Everyone loves the idea of a brand-new shiny SAN or NAS infrastructure. However over time this new infrastructure needs to be maintained. Not just at the driver level, but eventually arrays, fabrics and so on. So, data migration will become a continous BAU process we'll all have to adopt. Whilst I think further, I've distilled the requirements into some simple criteria:

Migration Scenarios

Within the same array
Between arrays from the same vendor
Between arrays from different vendors
Between similar protocol types
Between different protocol types

Migration Methods

Array based
Host Based
3rd Party Host based

Migration Issues

Performance – time to replicate, ability to keep replica refreshed
Protection – ensuring safety of the primary, secondary and any replicated copies
Platform Support – migration between storage technologies
Application Downtime – ensuring migration has minimum application downtime

Migration Reasons

Removal of old technology
Load balancing
Capacity balancing
Performance improvements (hotspot elimination)

Time to do some more thinking about filling out the detail. Incidentally, when new systems are deployed, a lot of though goes into how to deploy the new infrastructure, how it will work wth existing technology - how much time goes into planning how that system will be removed in the future?