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Virtualization Is Not All Roses
An anonymous reader writes "Vendors and magazines are all over virtualization like a rash, like it is the Saviour for IT-kind. Not always, writes analyst Andi Mann in Computerworld." I've found that when it works, it's really cool, but it does add a layer of complexity that wasn't there before. Then again, having a disk image be a 'machine' is amazingly useful sometimes.
This is the exact same pattern that almost every computing technology follows. First the lemmings all rush to sound smart by touting it's benefits. Soon it is the be all and end all in "everyone's" mind. Then the honeymoon fades and people realise it's a useful tool, and toss it into the chest with all the other useful tools to be used where it makes sense.
One of the most uninformative articles ever to hit Slashdot.
"Oh, so now more apps will be competing for that single HW NIC?" Wow. Computerworld, insightful as ever.
I want those 2 minutes of my life back...
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Really Cool Thing can have drawbacks. Popular computer technology shown not to be silver bullet. Film at 11.
how about an article that makes some recommendations on how to mitigate the problems they identify with virtualization, or point out some non obvious issues?
philo
If your servers become toast, due to whatever reason, you can get a simple workstation, put a ton of RAM in it, and load up your virtual systems. Of course they will be slower, but they will still be running. We don't need to carry expensive 4 hour service contracts, just next business day contracts, saving a ton of money. The nice thing for me with Virtual servers is it is device agnostic, so if I have to recover, worst case, I have only one server to worry about NIC drivers, RAID settings/drivers, etc. After that, its just loading up the virtual server files.
What are we going to do tonight Brain?
But it still is useful. Like terminals hooked up to big mainframes, it may make sense to run multiple virtual machines off a single server, or even have the same OS run for the same user in different spaces on a single machine. We have been heading to this point for a while, and now that we have the power, it makes little sense not to use it.
The next thing I am waiting for are very cheap machines, say $150, with no moving parts, only network drivers, that will link to a remote server.
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or, of course, you can use a faster network connection to the host, simplifying cabling. it might not be cost-effective to even go to GigE for many people at this point with one system per wire. For a lot of things it's hard to max that out, obviously fileserving and the like is not such an application, but those of you who have been there know what I mean. But if you're looking at multiple cables to each server and the attendant nightmares it may be just the reason you need to justify that new switch purchase.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I find Virtualization to be great for home use.
It's safer to browse the web through a VM that is set to not allow access to your main HD's or partitions. Great for any internet activity really, like P2P or running your own server; if it gets hacked they still can't affect the rest of your system or data outside of the VM's domain. It's also much safer to try out new and untested software from within a VM, in case of virus or spyware infection, or just registry corruption or what have you. I can also be useful for code developement within a protected environment.
Did I mention portability? Keep back-up's of your VM file and run it on any system you want after installing something like the Free VMWare Server:
http://www.vmware.com/products/server/
or VMWare Player:
http://www.vmware.com/products/player/
And if your VM gets infected or something, just delete it and make a copy of the backup, rinse & run!
I would say that every single one of those points in the article are being addressed in the enterprise VM arena. In the end due to the raw extra control you get over virtual machines it very much is the future. There is very little memory overhead. Once virtual infrastructure becomes fully developed and the scene plays out completely I think it will actually make the things in the article easier, not harder. You have to pace yourself in how and where you use virtualization in your organization, but the benefits are huge for the right environments.
As far as current day performance goes: disk access is essentially close to if not at native speeds and CPU speed is generally 70-80% of what the native processor can do. Most instructions aren't touched by a virtual machine monitor at all. Memory is more or less untouched and you actually get memory savings. Say you have 4 VMs of Windows 2003 running. All of the pages of memory that are the same (say, core kernel pages and the like) get mapped to the same physical page. The guest operating systems never know. You can effectively scoop up a lot of extra memory if you have a lot of systems running the same software. All of those common libraries and Windows/Linux processes are only paid for once in memory. The technology is simply awesome. In a few years with more and more powerful multicore systems virtualization will make more and more sense, even on performance critical systems.
It has its problems, but I am a believer.
Why is it all of a sudden whenever someone says "Virtualization" they imply that it must be Vmware/Xen/windows/x86 platform.
It's not like these issues haven't existed on other platforms. Mainframes, mini's (as400), Unix (aix/solaris/hpux), heck we've had it on non-computer platforms (VLANs anyone...).
And yes using partitions/LPARs on those platforms required *GASP* planning, but in the age of "click once to install DB and build website" aka "Instant gratification" we refuse to do any actual work prior to installing, downloading, deploying...
How about a few articles comparing AIX/HPUX/Solaris partitions to x86 solutions...
No, no, no. First of all, in a real enterprise type solution (something this author seems unfamiliar with) the entire environment is redundant. "the" server? You don't run anything on "the" server, you run it on a server and you just move the virtual machine(s) to another server as needed when there is a problem or maintenance is needed. It is actually very easy to deal with hardware failures.. you don't ever have to schedule downtime, you just move the VMs, fix the broken node, and move on. For software maintenance you just snapshot the image, do your updates, and if they don't work out, you're back online in no time.
In a physical server environment, each application runs on a separate box with a dedicated network interface card (NIC), Mann explains. But in a virtual environment, multiple workloads share a single NIC, and possibly one router or switch as well.
Uh... well maybe you would just install more nics? It seems the "expert" quoted in this article has played around with some workstation level product and has no idea how enterprise level solutions actually work.
The only valid point I find in this whole article is the mention of additional training and support costs. These can be significant, but the flexibility and reliability of the virtualized environment is very often well worth the cost.
-Lod
Indeed. If you have a proper ESX configuration: At least two hosts, SAN back-end, multiple NIC's, supported hardware - you'll find that almost none of the points are valid.
Teaming, hot-migrations, resource management, and lots of other great tools make modern x86 virtualization really enterprise caliber.
I think that the people that see it as a toy are people that have never used virtualization in the context of a large environment, being used properly with proper hardware. You can virtualize almost any server if you plan properly for it.
In the end, by going virtual you end up actually removing so much complexity from your systems that you'll never know how you did it before. No longer does each server have it's own drivers, quirks, OpenManage/hardware monitor, etc etc. You can create a new VM from a template in 5 minutes, ready to go. You can clone a server in minutes. You can snapshot the disks (and RAM, in ESX3) and you can migrate them to new hardware without bringing them down. You can create scheduled copies of production servers for your test environment. So much more simple then all-hardware.
I'll admit that you shouldn't use virtual servers for everything (yet) but you will eventually be able to run everything virtual, so it's best to get used to it now.
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I'm managing VI3 and we use it for almost everything. Ran into some trouble with one antiquated EDI application that just HAD to have a serial port. That is a long discussion, but for reasons I'm quite sure you could guess, I offloaded it to an independent box. We run our ERP software on it and the vendor has tried (unsuccessfully) several times to blame VMWare for issues.
You don't mention it, but consolidated backup just rocks. I have some external Linux based NAS machines that use rsync to keep local copies of both our nightly backups and occasional image backups at both sites.
Thanks to VMWare, it's like I've told management--"Our main facility could burn to the ground and I could have our infrastructure back up and running at our remote site before the remains stop smoldering much less get a check from the insurance company."
While I completely agree with you on this at many other areas, I don't in this case.
The reason for this is that virtualization -simplifies- tech support in every way (except for real-time applications).
Load problems, especially in a virtualized environment are extremely easy to manage technically.
You can just add additional servers and move the virtual machine to the new machine while it's running.
It's the management who will be having a budget problem when this happens, while tech support is not having a technical problem.
It's a toolbox. Regardless of if you are in IT or a mechanics shop, you need the right tools for the right job. I'm so tired of hearing at work how better one language is to another, or how this technique is superior to that technique. It's all a matter of what your trying to accomplish. You should ask your self if this best accomplishes the mission or not. Everything has it's +'s and -'s, just be a Man(Woman)and accomplish the mission. Get the job done, and use the tools available to you that best accomplishes the tasks at hand in the most timely manner.
Examine that quote from the article closely. See anything there that indicates virtualization "doesn't work"? No, nor do I. What they are talking about here has nothing to do with how well virtualization works, what they're complaining about is that a particular tool requires competence to use well in various work environments. Well, no one ever said that virtualization would gift brains to some middle level manager, or teach anyone how to use an office suite, or imbue morals and ethics into those who would steal; virtualization lets you run an operating system in a sandbox, sometimes under another operating system entirely. And it does that perfectly well, or in other words, it works very well indeed. I call FUD.
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basicly you spend a lot i mean a damn lot of money on super fast hardware and expensive SAN's
Most people forget there was also a term called "outscalling) that is, having multiple cheap machines running your applications.. You might not even use clusters hey try it real cheap and distributed.
Try 8 desktops with no SAN runnig your mail, instead of 1 virtualized cluster (for about the same price) okay one may crash but that only affects 1/8 of your users. Compare risk to money efficiency, and valeu, try to determine your costs. As no crashes with an extreme cost isnt a real solution to my opinion. it is Costs what should decide this. And to be true most companies (altough they claim it can not) can have a server down for a hour. And 1 hour is a long time for restoring 1/8 of your users mail.
I'm focused on mail server but it could have SQL or whatever too.
In my opinion this are nightmare solutions altough they give me lot of work.
But thinking of how much money is spend for it makes me shame
As there are better ways to put your money away.
Oh and i'm not thinking this alone there more specialists silencly talking about this, but afraid to say it out loud. I think it should be told more often.
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