Our last two weeks of romping through the undergrowth of technology surrounding the Intradyn RocketVault touched on the device's SyncDR feature. SyncDR allows near real-time, block-level synchronization of an SMB/CIFS share with a remote storage system that runs Secure Shell and rsync.

As we discussed, this remote system is preferably a Unix system, but Windows running Cygwin has been used (the limitation under Windows/Cygwin being a maximum file size of about 2G bytes).

When configured, the RocketVault SyncDR service contacts the remote storage device and makes a connection to the remote SSH service. After exchanging encryption keys and establishing a session, the RocketVault invokes rsync (which doesn't have to be running as a daemon). After that, any change made on the source share will be copied to the remote storage system.

A minor gotcha is that if the RocketVault cannot contact the SyncDR remote location - for example, if a firewall is blocking the SSH port (Port 22) - the RocketVault will hang waiting for a reply. It would be nice if the RocketVault interface could test the remote location by pinging it and recover gracefully on failure.

The only snags with backing up remotely are that all client machines to be backed up need to be powered on and any files that are held open by applications or the operating system cannot be backed up (this includes operating system files, the Windows registry, Active Directory subsystem, application files and data files).

The former can be solved easily with a strip of duct tape over the big red switch while the latter is a little more problematic. A solution to this problem is Intradyn's BackAgain software that runs on the machine that is the source of the back-up data. BackAgain, available in both Windows server and workstation versions, can save backups on a RocketVault, a remote disk drive, or any standard tape drive.

When BackAgain encounters a file opened in exclusive mode it makes several attempts to back up the file before giving up (as opposed the RocketVault's single attempt). To ensure that files permanently opened in exclusive mode (which is the case with many operating system files) are backed up, Intradyn recommends Open File Manager (OFM) from St. Bernard Software.

OFM operates by tracking file transactions and cache changes that begin when a back up is started, providing the back-up application - in this case BackAgain - with a snapshot of all file data at the time the backup started. OFM allows live backups of any application.

We mentioned last week that the RocketVault has a few rough edges. Certainly it should be easier to set up the device and the documentation could do with an overhaul, but Intradyn pointed out that this product is usually set up by a dealer so the majority of users never will have to wrestle with these issues.

What users will have to deal with are the e-mail reports that the RocketVault generates. The reports are gobbledygook -unremittingly techie and full of extraneous detail that make them look more like debug traces designed by a committee of engineers who obviously had never met a live end user. It's not that you can't understand the reports, it's simply that the reports are overly hard to understand. Intradyn says this is on the list of improvements it is working on.

Despite our criticisms we really like the RocketVault. It works well, is reliable and delivers an excellent bang for the buck. The RocketVault line starts at about $1,500 with a 120G-byte drive (with compression this equates to roughly 250G bytes).

Speak your mind at gearhead@gibbs.com.