The key, says Blakeley, is migrate "stale" data quickly onto tape. He says 80% of Mazda's stored data becomes stale within months, which means that blocks of data aren't accessed at all.
To accommodate these usage patterns, the virtual storage is in a tiered structure: fast solid-state disks connected by Fibre Channel switches for the first tier, which handles 20% of the company's data needs. The remainder of the data is archived to slower disks running at 15,000 rpm on a Fibre Channel system for a second tier, and a third tier of 7,200-rpm disks connected by serial-attached SCSI.
Blakeley says Mazda is putting less and less data on tape -- about 17TB today -- as it continues to virtualize storage.
Overall, the automaker is moving to a "business continuance model" as opposed to a pure disaster-recovery model, he explains. Instead of having backup and offsite storage that would be available to retrieve and restore in a typical disaster-recovery scenario, "we will instead replicate both live and backed-up data to a colocation facility."
In this scenario, Tier 1 applications will be brought online almost immediately in the event of a primary site failure. Other tiers will be restored from backup data that had been replicated to the colocation facility.
Boosting speed with an appliance
The Nielsen Company, the ratings service that helps determine how long TV shows stay on the air, analyzes the audience for local shows in about 20,000 homes and tracks national shows in about 24,000 homes. After various steps -- including calculation, analysis and quality assurance -- the ratings are released to clients within about 24 hours after the initial telecast.
Scott Brown, Nielsen's senior vice president for client insights, says the data is collected in a central processing facility in Florida and some 20TB of data is then stored in Florida and in Ohio. The company uses a series of high-speed SANs and network-attached storage, mostly from EMC, although Brown declined to provide specifics.
Much of the process of generating reports from Nielsen's data warehouses is automated, but there is manual control too. Employees can call up data about a specific report from years earlier, and managers can create custom reports about viewer data.