Constant Data Plays Linux Card

Storage management software startup Constant Data Inc. has launched a new version of its host-based replication software, claiming it's the only product of its kind aimed at Linux environments -- although that's a differentiator it probably won't be able to trade on for very long.

The Minneapolis company, founded in early 2002, has been quietly shipping the first versions of its Constant Replicator software since last November. With the availability of the 3.0 version of the software, the company says it has greatly improved its replication of databases, large data sets, and rich media content. And unlike previous versions, the new software version guarantees write-order fidelity and transactional integrity, the company says.

While remote data replication used to be the prerogative of only very large businesses and institutions, a growing number of host-based replication offerings like Constant Data's are driving down the price of the technology and allowing even small businesses and remote offices to mirror their data offsite, thus safeguarding them from local outages or disasters (see our report on Data Protection).

Constant Data's software -- which runs on Linux, Solaris, and AIX -- allows companies to synchronously journal all file changes on their local application server, before asynchronously mirroring the data to a remote site. This ensures that the data is continuously backed up and that there is always a nearly up-to-date remote copy of the data. At the same time, processing at the primary site isn't slowed down from waiting for a receipt from the secondary site before continuing. And since the mirroring between sites doesn't have to be in sync, companies are free to send data over ordinary networks and use cheaper storage at their secondary site.

The software, which journals all changes in real time, doesn't have to go through the file systems and can therefore easily scale, says Paul Sustman, Constant Data's president and founder. "The benefit is that it works as fast with 10 Mbytes as with 10 Tbytes of data," he says. "Scaleability is the main advantage of a real-time system."A number of host-based replication products are already on the market, including software from Legato Systems Inc. (Nasdaq: LGTO), NSI Software, RepliWeb Inc., Veritas Software Corp. (Nasdaq: VRTS), and XOsoft (see NSI Notches $15M and XOsoft Turns Back Time).

Constant Data claims, however, that missing from the equation so far has been a product in this space targeting Linux environments. "We offer the first Linux real-time data replication solution," Sustman says. "And it works cross-platform between Sun Solaris servers and Linux servers."

But industry observers say other players are surely not far behind on Linux. "You can bet without a doubt that the big players are going to be doing host-based replication on Linux," says Enterprise Storage Group Inc. analyst Steve Kenniston in an email. "The other thing not to discount is the fact that array-based replication doesn't care what the OS is, and is still the leader in replication technology."

Still, the array-based products are way out of the league of many of the customers Constant Data is targeting. For example, EmbekTek, a small division of Brunswick Corp., is currently using a previous version of Constant Replicator to mirror only a couple of gigabytes per day, according to division VP Tom Varghese. "This allows me to sleep well at night," he says. "If we miss a couple of tape backups, I don't worry about it too much; and if the machine crashes during the day, it's not a problem. We still have most of our data."

The division, which employs 20 people, was looking for a way to inexpensively secure its data in between its nightly tape backups. "We didn't see anything else in the same price range as Constant Data," Varghese says. "The copying is fairly instantaneous, it's very transparent, and it's extremely easy to use." He says that the company is currently replicating data to a server sitting right next to the primary server, but is planning to add remote-site replication as soon as its budget allows.Constant Data, which is privately funded (and would not disclose details of its finances), says it has four direct customers already using its Constant Replicator software. In addition, the company has 12 reseller deals with companies in the U.S., Germany, Korea, and Japan.

Constant Replicator 3.0 has a list price of $2,995 per server, regardless of the amount of storage it's being used for, the company says.

Eugénie Larson, Senior Editor, Byte and Switch