主题：有谁能谈谈虚拟数据中心的事情 -- 川江

Virtualization is not a new technology, mainframe back in 60's using virtualization technology such as VMS.

Virtualization to IT is just insert another layer, which offer flexbility, HA, DR and other benefits.

Virtualization happening not only in Wintel environment, but UNIX as well, each vendor has its own flavor, like IBM AIX has lPar, and HP-UX has vPar and Sun Solaris has Zones. in x86 world, VMware has lead, so that's why lots of people thinking virtualization means VM servers.

in network world, vLan is virtualized LAN. now all Cisco's switch are virtual too. and Firewalls are also vFW instead of physical (one physical firewall box can support multiple instances of virtual firewalls)

in Storage world, vSAN also start to get implemented, right now, just some vendor insert a management layer to extend one single management interface to various SAN and NAS devices.

almost every IT technology now have a virtual layer.

in a typical mature enterprise IT environment, I have seen virtual to physical (server instance wise) ratio could be as high as 5 to 1, means, 80+% of servers are actually virtual.

Even big Database boxes that traditionally not a good candidate for virtualization also get virtualized in some environment, not to gain any footprint reduction, but to get benefits associated with that virtualization layer.

Cloud computing will leverage some virtualization technology to make it more efficient. but cloud itself is a different concept than virtualization.

Cloud means get your computing power outsourced to others, instead of hosting all the processing power locally to data center, move them to cloud provider, while they can do it more securely, more efficient at less cost. (at least that's the goal). it currently pretty attractive to small business, mid to large enterprise still need to host their own data centers.

so for example, instead of store all your document locally on your home PC, you upload all to Amazon's could account, while you can access them anytime, anywhere. google picasa is another example.

Could computing is the same concept as ASP (Application service provider), in that you just use the whole software as utility, you don't care about how it is hosted, maintained, etc.

it has great applicability in some common software area such as CRM. but not so much in business know hows and key competitive advantage areas, like Walmart will not use cloud to host its supply chain for sure.

sorry I use english for all these, probably will take 4 times more if I type all those in Chinese.