Are Virtual Dedicated Servers Worth The Cost?

xtremex asks: "I just had an online conference with a company called Ensim and they have made an appliance that takes all the servers in your data center and chops them into 'virtual' dedicated servers, so instead of a dedicated server client wasting 50% of his space and server power, it'll take one server and issue a percentage of processor power, memory and disk space, each virtual server having their own root password, etc., and a Web based control panel for both resellers and owners...this thing got me salivating..until the told me the price..$25,000. I almost fell off my chair. It looks REALLY good, but is it worth $25,000? They even offered to come down and install it and I have the unit for 30 days free..Does anyone know about this amazing product? Is it worth the price?"

Awful lot of money for such an old problem

[bgalehouse]

Unix people have been building time sharing systems for a long time. For 25k, I'll bet that I can get pretty close to this sort of thing. Let's take an inventory of what you really need.

1. You want each client to run and admin their own webserver.
2. You don't want each client to be able to affect the others. This means no rampant interfering resource usage.

Now, lets talk about how one might do this using off the shelf stuff.

1. Two ways to run multiple indepentenly admined web servers come to mind:
   • The new FreeBSD kernel supports the jail [freebsd.org] syscall. This can attach collection of processes to a particular ip address. I rather suspect that this is exactly the sort of thing that it is meant to be used for.
   • On linux, you can permission individual ports. Each client runs their webserver on a different port. Use ip masquerading to redirect connections to diffent ips (port 80) to different ports (localhost).
2. Unix timesharing systems have been hit with all sort of internal dos attacks. My personal favorite is the shell script which does nothing but call itself in an infinite loop. Hence the creation if killall. All of these attacks (which can be negligence as much as anything intentional) have defenses. Unix is meant to be multi-user, even if we forget in the PC-laden age. We have:
   • Quotas [freebsd.org] - x% of the hard drive, coming right up.
   • Process limits [freebsd.org] - With not too hostile users, it shouldn't be too difficult to keep their web servers from running away. Note that csh [freebsd.org] is the ussual interface to this functionality.

So what do you really get for your 25k? My guess is a little bit of convenience. Maybe a bit of transparency to your users - don't have to tell them it is a shared box if you replace login to use per ip password file, could rewire the reboot command to do a kill for the users in question and rerun 'their' /init.d scripts, etc.

And if this package doesn't take off and becomes unsupported... then where are you? It doesn't quite sound like the sort of thing which will work with the next version of whatever OS it is for. Unless it is a colletion of perl and shell scripts (about what I would use), in which case you could patch it up if necessary. Do you get a source code license for your 25K? Is their customer care any good?

It might be worth it, if they make it truely easy to multi host, and give you a source license, and you are short of rack space and/or using really expensive boxen. But I wouldn't bet on it.

Re:One word: No

[empath]

Hey, so we should avoid PVCs, VPNs, and VLANs? I know of a few companys that would be not very happy upon hearing your advice, including some phone companys.

An awful lot.

[Wakko Warner]

Reread what he wrote. He wants to limit resources and CPU, not start another copy of Linux for each person running a webserver.

- A.P.
--

"One World, one Web, one Program" - Microsoft promotional ad

Commercial folks do this all the time...

[Anonymous Coward]

Although Sun's products don't split multiple domains across a single CPU, the high-end Sun servers provide the facility to have multiple 'domains' or "virtual" computers running on a large system. Lots of people do this with their E10ks, partitioning them into three or four different servers.

IBM's VM mainframe systems also kind of do this (I'm not overly informed on their internals.) Essentially you can have multiple "virtual machines" on a single mainframe.

Again this technology/cost shows that once again Linux can now be made to jump through the same flaming hoops that other OSes were doing years and years ago. Sure, it can do it cheaper but is using PC hardware the right solution?

Lots of people(tm) (Sun client sites, large enterprise shops) use those multiple 'virtual machines' as a true development environment. They'll have one VM setup for "development" another for "test" and another for "production." The development VM can be rebooted and messed with all the time... the "test" VM takes frozen code from devel VM and tests it through. The production VM is where the stuff actually runs.

Re:Awful lot of money for such an old problem

[titus-g]

don't have to tell them it is a shared box

You'd have to make absolutely sure they couldn't find out though, get your employees to sign a contract that they are to forgo all alcohol, recreational drugs etc while they are in your employ.

If I was renting a dedicated server and found that it was just a higher grade virtual one I would be pretty pissed off, even if I WAS getting the same performance/features as true dedicated. Also it probably wouldn't be legal...

The alternative would be to admit to it, but then I don't think you could charge so much.

Would be ok for an in-house system though if it saves enough costs compared to having seperate servers.

Re:Awful lot of money for such an old problem

[bgalehouse]

Yeah. I guess it would be hard to put anything meaningfull on the contract about what sort of box they are getting for their money.

Guess it depends on how clued in your user's are, and how good you are at social engineering. Not that I am advocating this "hide the timesharing completely" approach in any way shape or form.

That's not a dedicated server

[RomulusNR]

Let's take an inventory of what you really need. You want each client to run and admin their own webserver. You don't want each client to be able to affect the others. This means no rampant interfering resource usage.

No. You've confused "dedicated server" with "virtual host". Which may be understandable, given the title of the article. But these are not the same thing. With a dedicated server[1]:

1. Customers want to be able to run servers and apps beyond just HTTPD and its front/backends.
2. Customers want the freedom and control of root access, and don't want anyone else to have it. (In some cases, not even the hosting provider!)
3. Customers don't want to worry about anyone else clogging their server's pipe.

Providing the first two items to multiple customers of the same box is going to be messy on any OS you come across. The product being described is interesting, but the price tag is excessive. One wonders what sort of installations will be able to turn a profit. My workplace has maybe 4-5 dozen deds. Being able to condense some of the lower-usage customers might free up a handful of boxes. Would it be $25,000 worth? I don't know.

On the other hand, I wonder how they can address the third item. If two customers on the same ded suddenly ring up a lot of traffic at the same time, there could be contention, which would cause both customers to cry foul.

Not only that, but you'd either have to cheat your customers, or you'd have to be up front about the fact that you're not really giving them a DEDICATED server. [2] And then, you wouldn't be able to charge as much. Thus cutting into the margin you would need in order to make up for the cost of this product.

It seems to me if your users' aren't using their full capacity, that's great. They're paying you for something they aren't using, and you're making more money off them. If they are spendthrifts, that's their problem. If a dedicated server is more than they need, then they should get a vhost and be happy.

[1] This reflects the definition of "dedicated server" used by my employer, Shore.Net. YRMV. Incidentally, the term is being phased out in favor of "managed colocated server".
[2] "Shared dedicated server" is an oxymoron.

Re:Awful lot of money for such an old problem

[Anonymous Coward]

I am an employee of ensim, and this reply is NOT an official position or reply of the company, but I would like to clarify a little what ensim offers and what the 25k buys you.

The 25k is an upfront investment in a server that will manage and provision your whole datacenter, that box is not the one doing the hosting. What it does do is takes racks of servers and turn them from share virtual hosting boxes into 'virtual' dedicated hosting servers. We have 21 patents pending on our virtualization technology that DOES in fact limit CPU, bandwidth, memory, and disk per a private server.

The value here is that for 25,000 you will be able to manage your datacenter with less IT resources as well as save rack space. The cost savings could be huge. Our virtualization technology has also been tuned to perform VERY well in a hosting environment unlike other companies that are trying to do a general purpose virtualization solution.

In addition, we provide a easy application delivery platform with ServerXchange, deploying new apps for hosted customers is as simple as drag and drop.

Ensim ServerXchange

[Paul Menage]

Ensim ServerXchange effectively costs $250 per machine: the $25,000 box is a provisioning box which can provision up to 100 other machines. Each of the provisioned machines can then be chopped up into private servers with a percentage of memory, space and processor power. You also get:

• an integrated suite of web- and Java-based applications providing control and management for the service providers, their resellers, and their users;
• a large number of applications and application suites that can be installed en-masse on private servers with just a few mouse clicks.

To answer questions raised in other comments:

What's the difference between this and installing VMware for $329?

Even though an Ensim private server appears to the applications running on it to be a dedicated server, it runs in the same operating system as the host. This means that it can take advantage of services provided by the OS with much less overhead than VMware, in terms of both CPU and memory usage.

How is this different than traditional load balancing / clustering / virtual web hosting and the like? Where is the real benefit?

A private server is a fully featured virtual machine and provides a lot more flexibility than traditional web hosting. It is cheaper than a dedicated server (both for the ISP/ASP and the customer) while providing guaranteed resource allocation.

...there is absolutely no way in modern operating systems to allocate CPU space to a group of processes.

We can do it :-)

Unix timesharing systems have been hit with all sort of internal dos attacks. My personal favorite is the shell script which does nothing but call itself in an infinite loop.

If you do this on an Ensim private server you will only hurt that private server itself. Other private servers running on the same box will not be affected.