WAN optimization is not something that storage vendors traditionally put into their storage controllers. Storage replication traffic has to fend for itself out in the WAN world, and replication performance will usually suffer unless there are specific WAN optimization devices installed in the network.
For example, Netapp recommends Cisco WAAS as:
“an application acceleration and WAN optimization solution that allows storage managers to dramatically improve NetApp SnapMirror performance over the WAN.”
“…the rated throughput of high-bandwidth links cannot be fully utilized due to TCP behavior under conditions of high latency and high packet loss.”
EMC similarly endorses a range of WAN optimization products including those from Riverbed and Silver Peak.
Back in July, an IBM redpaper entitled “IBM Storwize V7000 and SANSlide Implementation” slipped quietly onto the IBM redbooks site. The redpaper tells us that:
“this combination of SANSlide and the Storwize V7000 system provides a powerful solution for clients who require efficient, IP-based replication over long distances.“
Bridegworks SANSlide provides WAN optimization, delivering much higher throughput on medium to high latency IP networks. This graph is from the redpaper:
Bridgeworks also advises that:
“On the commercial front the company is expanding its presence with OEM partners and building a network of distributors and value-added partners both in its home market and around the world.“
Anyone interested in replication using any of the Storwize family (including SVC) should probably check out the redpaper, even if only as a little background reading.