News from at least one vendor this week begs the question: Is it easier to replicate in virtual environments than in physical ones?
DataCore Software announced yesterday that Tokyo-based SoftBank Telecom used its SANmelody software in a proof-of-concept (POC) project featuring remote-site mirroring of a Tokyo data center in Osaka, Japan, about 500 kilometers away. The setup is part of a planned design to support new services from SoftBank, DataCore says.
In the POC implementation, DataCore's software resides on a dedicated server in an InfiniBand-based network (based on Bay Micro switches). Another server in the network runs VMware ESX and VMware's ESX HA (high availability) software. Virtual machines generated by the VMware hypervisor use the DataCore server to front-end about 32 Tbytes of Fibre Channel storage (from IBM's DS Series). The DataCore server creates shared storage and in turn uses multiple "virtual iSCSI HBAs" created by a connected appliance from Xsigo as the networking mechanism for mirroring data between sites. The Xsigo appliance works with the router to send the data over the WAN via Sonet.
"It is clear that the combination of virtual storage and virtual servers in an overall virtual infrastructure make it much easier to do disaster recovery," stated Peter Thompson, VP of Asia Pacific for DataCore.
But industry sources say storage managers face the same issues of performance, manageability, and vendor lock-in, whether they're replicating data from virtual machines or "real" ones.