Wrongful manual configuration changes of large SANs could be identified and avoided with Onaro's SANscreen product, according to Cisco.

Large SANs, ones with a thousand or so ports, are likely to have nearly daily changes in configuration. LUNs can be redefined, port cabling altered, users and switches added. Virtual SANs could change more often as they are altered to match the business neeeds. Such changes when carried out manually are prone to error with unexpected consequences needing much time and effort to diagnose and fix.

SANscreen automatically discovers a SAN's components - both Fibre Channel and iSCSI - and builds a model of the configuration. It can diagnose existing errors, using root-cause analysis, and help in their correction. A predictive facility means that proposed changes can be tested against the model and mistakes identified and corrected before being applied to the actual SAN. The software works with Cisco's MDS9000 director and switches, including Cisco's VSAN - virtual SAN feature.

The Enterprise Strategy Group's Steve Duplessie reckons that nearly half of application downtime in businesses with large SANS is due to manual SAN configuration changes. He states, "The Onaro SANscreen product is one of the smartest things I’ve run into in years. I personally have been long complaining about a lack of modelling abilities in our storage management platforms, and let’s face it – any tool that helps us eliminate problem resolution guesswork is welcome."

This ability to test out changes and diagnose errors in SAN configurations is not a general feature of storage resource management or other SAN management software, according to Onaro. The company is working with a number of partners: EMC; Cisco, Hitachi Data Systems; HP; QLogic and Brocade for example. This helps with the auto-discovery and also means SANscreen works with, for example, EMC's ControlCenter management software.

The software is agent-less and uses out-of-band network bandwidth, meaning no impact on SAN data access.

Its use can mean that fewer storage admin people are needed to fix problems. Robert Shinn, a principal at State Street Global Advisors, which offers investment services in the US, said they needed 20 administrators to look after changes to their 1,000-port SAN. The use of SANscreen enabled almost half of them to be used for something else.

It also means that companies can more easily consolidate SANs, previously kept apart to minimise the SAN-stopping effects of problems.

Duplessie said, "I can almost guarantee that once you try SANscreen, you will (a) immediately find a problem(s) you didn’t know about in your infrastructure and (b) wonder how you lived without it."

SANscreen does not yet work with tape devices attached to the SAN. Pricing begins at a $64/port level; about £35 at current conversion rates. Onaro says an initial system can cost less than $50,000 - about £27,000.