Virtualization?

[davej]

So I was reading about how virtualization is a critical technology that makes fault-tolerant server clusters possible. Does anyone (or everyone) here have experience with this stuff? http://www.vmware.com/products/datacenter-virtualization/vsphere/overview.html

Edited December 3, 2012 by davej

[justsomeguy]

Experience with virtualization in general? Most cloud computing platforms use virtual servers.

[davej]

Experience with virtualization in general? Most cloud computing platforms use virtual servers.

So is the 'cloud' a different animal than the typical web hosting service?

[boen_robot]

I don't know about "fault tolerant", but a virtual server certainly allows providers to give more power to the user without a security risk or hardware costs.From a software point of view, a virtual server is the same as a real server. From hardware point of view, MULTIPLE virtual servers run on the same hardware, without interfering with each other, so it's "as if" you have multiple devices... except not really.In addition to cloud providers, there are "Virtual Private Hosting" (VPS) providers, which are basically like a dedicated server - you have full access to the OS and all of its software and settings - except that the hardware is shared with other VPS instances though virtualization. Because of this, VPS is generally more expensive than shared hosting, but cheaper than "actual" dedicated hosting.To be on a cloud provider is a little different from being on a VPS. A VPS is still a single server. Sure, most providers also keep backups for redundancy, and (here's perhaps where the "fault tolerant" thing comes from) they can recover a VPS from one hardware onto a different hardware if the old one fails.A "cloud", if the provider is actually being honest (rather than abusing "cloud" as a buzzword), means that the thing you're seeing as a single server is actually a collection of servers, which are typically multiple VPS instances, but could also be dedicated servers. You don't know, and (the key bit) you don't need to, as the provider ensures you're working as if you're on a single server, while they take care of balancing the load and ensuring there's enough servers to power your site.

[davej]

Yes, I skimmed through Amazon's AWS service options and it seems that it is all based on vmware virtualization using server clusters. The AWS cost seems to be difficult to estimate since the various pricing schemes are very confusing. I guess ordinary VPS is something like US$50-$75 per month. http://aws.amazon.com/ec2/http://www.vmware.com I had thought the Amazon cost was something like US$175/month and up but this calculator seems to say it can be much less than that although I'm not sure how you can know how many "hours" to enter. http://calculator.s3.amazonaws.com/calc5.html

Edited December 23, 2012 by davej