Ever since hard disks were deemed critical to data processing, storage suppliers have devoted much effort to circumvent hardware failures. It started with basic disk mirroring and then evolved into the various RAID protection levels in attempts to reduce the cost of redundancy. As external disk subsystems became popular, vendors added redundancy to other components whose failure was considerably more catastrophic; fans, power supplies and disk controllers come to mind.
It’s now commonplace to regard storage products as offering “high-availability” (HA) simply because they have internally redundant hardware. This interpretation creates the expectation that you can always get to data on disks. But this is far from reality.
In effect, better storage products have shifted the risk from hardware failures to data outages. Protecting against these outages is particularly important in environments where numerous workloads depend on centralized storage devices. Take, for example, server and desktop virtualization. The costs and difficulties to schedule storage-related downtime are 10 to 30 times more than they were when all these tasks were spread across isolated servers with their own separate disks. That’s why the requirements for HA storage must encompass the prevention of downtime, not merely shielding against component failures.
Why? Because “stuff” happens and all too often we don’t assume a disaster will actually occur until it’s too late. And can your business survive without having access to the storage and applications? One lesson from the bombing of the World Trade Center in the ’90s was that companies that failed to have a Disaster Recovery plan in place failed. In fact, 150 businesses out of 350 failed to survive the event.
If you’re serious about HA, you shouldn’t be compromising data availability; you should be looking for a better alternative. One excellent choice is a device-independent, software-based storage virtualization solution. The good ones can eliminate single points of failure in the storage infrastructure to prevent data loss and provide continuous data availability. Then you too can enjoy non-stop data access using attractively-priced storage devices from vendors you choose.
Don’t let the joke be on you when it matters most. Get serious about HA today.
