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For over a year now, Network Appliance has sold NearStore, a relatively inexpensive array which many storage managers use as a place to keep snapshots of production data from which they perform backups or recover data.
Now StorageTek has introduced a NearStore competitor that appears to have two major advantages over the NetApp product: For one, it is not tied to any particular computing environment, be it disk or host and two, it relies on journaling--not snapshots--so data can be recovered to precisely the time before a file was lost or corrupted.
Called EchoView, the system is comprised of an iSCSI disk appliance that receives data from protected servers with the help of a non-invasive server-side agent, says Dave Trachy, StorageTek manager of data management software. The system also requires the installation of a QLogic TCP/IP Offload Engine (TOE) card for each server, resold by StorageTek.
In a first release, the EchoView E400 will protect up about 400GB, depending on how long you journal for, and supports Windows, Linux and Solaris hosts. In a next release, StorageTek will introduce a larger model integrated with the company's BladeStore ATA disk array, support for Fibre Channel, as well as HP-UX and AIX hosts.
According to Dennis Martin, an Evaluator Group analyst, "using journaling in the context of backup" is a somewhat novel use of the technology. Many databases journal transactions in order to roll back the system in the case of a corruption,
EchoView's reliance on journaling is also fueling the development of a so-called "rewind" feature that lets you pick the exact point when a data corruption occurred, and undo, so to speak, any writes that were done since then. For recovery purposes, EchoView's rewind feature promises to be much faster than the current process: mounting to the journaled EchoView file system, and restoring the data via remote copy, Trachy says.
Using journaling as the basis of data protection is "the future of data protection" asserts Mike Rowan, CTO at stealth-mode start-up Revivio. The company is developing a product similar to EchoView's rewind feature, a sort of "Wayback Machine, like in Rocky and Bullwinkle," says Jon Toigo, founder of Toigo Partners International.
But journaling is not without its pitfalls, cautions Revivio's Rowan. "The problem that exists around journaling is that it keeps track of the stuff that you are overwriting," Rowan says. In other words, every time you go to write to a block, the system must first read the old block before it can rewrite it. This causes the system to generate extra I/Os, which in turn can cause quite a performance hit.
Like StorageTek's EchoView, Revivio's product--due out in the fall--"is loosely based on journaling." But unlike EchoView, Revivio has set its sights on protecting high-performance production database environments. The company's challenge, therefore, is to build a system that doesn't require server-side agents or impact performance.
Whatever the case, Revivio's product will provide better economics than current data protection solutions such as EMC's TimeFinder with its business continuance volumes (BCVs), Rowan promises. Products like those, he says, "cost enormously to implement, but still don't get you within 20 feet of where you want to be."
This was first published in June 2003