Managing Linux and Virtual Machines? 239
deijmaster asks: "For a couple of months we have been hearing (as a major consulting firm) IBM people pushing the possibility of installing a Z/Linux VM setup at one of our biggest clients (financial). To a Linux user such as myself this sounds great, at first. Now, I am a bit reluctant when it comes to managing this kind of infrastructure, with little or no local expertise at IBM. Has anyone gone through a Z/Linux VM corporate installation and lived through the management of such a solution?"
Linux/390 resources (Score:5, Informative)
Oh, and the Marist linux-390 listserver [marist.edu] is well worth subscribing to.
You WILL need help (Score:4, Insightful)
So you will have to get a VM person in. Probably only on part time contract, and IBM will can provide that person for an additional fee.
In time you may learn enough to support your very limited VM environment.
Re:You WILL need help (Score:5, Informative)
Actually VM itself is fairly straight forward to administer
The biggest hurdle will be:
This is also where security comes in. Each SVM is really isolated from each other.
One thing to remember too is that VM was (and still is) used by many Universities and colleges -- not as much as it was back in the 70's and 80's, but it still has a presence.
Anyway... just some comments from an old timer VM sysprog
Can you help out with some more info on vm tech? (Score:2)
I'm really interested in the whole virtual machine thingy, where CPUs, memory, etc. are virtualized.
Re:You WILL need help (Score:4, Insightful)
So you will have to get a VM person in
Yes, this is true, but if you are going to run Linux , you only need one VM person. The rest of your Admins should be Linux Admins.
Don't imagine that the VM person will understand (or even like) Linux and don't expect your Linux admins to understand (or even like) the Mainframe.
Re:You WILL need help (Score:5, Informative)
Actually not quite true (that the VM person won't understand or like linux).
Linux has actually given VM a shot in the arm. VMers are well aware of that fact. I support a couple of VM systems during the day and play around with Linux at home at night.
Also in terms of culture, I think you would be very surprised with the VM culture. VM spent many years as the unwanted child, VMers had to rely on each other in order to be heard above the MVS roar.
If you take a look at some of the history of the internet you will find VM sitting there (BITNET was basically a collection of VM systems). The listserv concept was originally from VM (CERN was -- might still be -- a big VM site).
If you want to see some of the history of VM you can start here: http://pucc.princeton.edu/~melinda [princeton.edu]
Re:You WILL need help (Score:3, Funny)
AC forgot to mention... Don't expect your Linux admins to understand (or even like) the VM person. ;)
Re:Don't forget..... (Score:2)
However, with today's prices, I'm pretty sure that $85-$100 per hour is doable. The days of "naming our Price", and them paying it are over, at least for the forseable future..
Re:Don't forget..... (Score:3, Informative)
Good luck at getting one in your door for under $160 an hour - if you sign a 1 year gig maybe but not for a few weeks.
I would advise against it (Score:4, Informative)
1. What exactly demands this solution?
2. Can a pure Linux box, with mild tweaking, still not be more useful and create less overhead than this?
Someone in this thread mentioned IBM implementing wildly complex systems in order to push consultation, and on some levels it's true. PeopleSoft does it also. In some cases, Oracle will have a go at this tactic. My advice is to do some searching first, without the input of IBM, and see if you can't find a better solution to whatever problem you're trying to remedy.
Re:I would advise against it (Score:3, Informative)
Clusters (Score:2)
Again, we need to know more about his institution's needs before we can confidently declare which solution (Z\Linux or a cluster) is the best fit for his needs.
Re:Clusters (Score:4, Insightful)
I know this is Slashdot, but a beowulf is not always the best choice!!!
Re:Mainframes (Score:4, Funny)
Have you ever dealt with a MAINFRAME? Large MAINFRAMES are fucking expensive to run 24x7x365. They require a lot of Air Conditioning (many people spend over $1,000 a month on just AC, that's an expense that is never going away), electrical and a shitload of space.
And he diffrence is what? For most applications, clusters, for all their faults are faster and cheaper than mainframes.
Re:Mainframes (Score:5, Interesting)
They're a heck of lot less wasteful (electrickery into heat) than they used to be, and require a lot less space (again, compared to the past).
Clusters ... I don't know where you get the 'faster and cheaper' line, unless you're talking about applications specifically designed for clusters. When you start writing apps designed for a few thousand simultaneous users, the benefits of the mainframe become apparent. Stability. Speed. The ability to hold gobs of info in ram. Which, BTW, makes them the nearly ideal web server. Security (hey, it's not M$!). Mainframes are a mature technology ... meaning lots of the annoying things (both hardware and software) still plaguing the small boxes have been fixed. (Admittedly, 'mature' often translates into 'f$cking obsolete pos' (i.e. panvalet).)
I don't worry about backups conflicting with apps on the mainframe. I don't worry about the details of storing things reduntantly (although that's quickly getting solved on the smaller boxes). For those things written on WinWhatever, the programmers need to worry about every little upgrade/patch from M$.
Now, most places still give mainframes a room of their own ... and it tends to be a bigger room than servers get. And, if you're happy with something a little slower and little less reliable, a good farm runs less than a mainframe.
But, to put things in perspective, one of my databases (non-mainframe) is moving to a USD 2.1 million machine. That's a fraction ... as in, from 1/4 to 1/20 (depending on options) of a mainframe.
I'm working in both worlds. I like the cost benefits of the smaller boxes. But it still freaks me out when users punch in a query and it takes several seconds (to minutes) for a response, when the delay on the mainframe is done by the time the enter key pops up.
Re:Mainframes (Score:2)
A box with a few 3GHz CPUs in it isn't CPU bound anymore - it is I/O bound (back and forth to the memory, hard drives, and users.) If a desktop box can get a 40% boost in performance by doubling the amount of on-CPU cache - that means it is outrunning the I/O o
Water cooling? (Score:2)
I guess the tubing logistics would be a pain in the * as well as the PSUs generating heat.
I just imagine since AC costs so much, that people haven't thought of any newer or different ideas to save cost in this aspect.
Any innovative solutions out there? This sounds like it could be good idea for a /. story.
Re:Water cooling? (Score:3, Interesting)
Later crays cooled themselves by using a liquid containing man made blood plasma that is used in blood transfusions.
Re:Water cooling? (Score:2)
Get a coolant leak and all of a sudden your server room looks like the opening party scene in the movien 'Blade'.
Re:I would advise against it (Score:2)
And that's just part of the story...
Re:I would advise against it (Score:5, Insightful)
Reasoning by analogy is always fraught with pitfalls.
The Ferrari can't carry more than two people. The IBM machine is designed for fast I/O. The Ferrari breaks down a lot. The IBM is designed to be highly reliable.
Perhaps a better, but still rather imperfect analogy would be to a tractor trailer--lots of horsepower, but not a speed daemon. Lots of cargo space. A decent diesel engine that can stand up to abuse.
IBM thinks that if you replace 20-30 Intel CPUs , all running at 5% utilization, with a single zSeries CPU running at 85-90% utilization, you'll save money and aggravation. On the other hand, if those 20-30 Intel CPUs are rendering CGI for a film, or modeling a jet engine (and thus running near 100% load), a zSeries CPU would only be able to take on the work of 4-5 Intel CPUs, if that.
Re:I would advise against it (Score:2)
Reasoning by analogy is always fraught with pitfalls.
Amen, brother.
IBM thinks that if you replace 20-30 Intel CPUs , all running at 5% utilization, with a single zSeries CPU running at 85-90% utilization, you'll save money and aggravation. On the other hand, if those 20-30 Intel CPUs are rendering CGI for a film, or modeling a jet engine (and thus running near 100% load), a zSeries CPU would only be able to take on the work of 4-5 Intel CPUs, if that.
The problem with economies of scale, quite frankly
Re:I would advise against it (Score:3, Informative)
you have to use their hardware despite the fact you can use hardware from Comp USA. The VPN prevents
Re:I would advise against it (Score:2)
Re:And here is the p series with Linux or AIX (Score:2)
If you have something cpu intensive, doing lots of floating point calculation then get yourself a pseries (a fancy name for RS/6000) - that's what they're good at and where they still beat the crap out of intel. Then you can pick either linux or AIX, although I'd picked AIX and install their "
No fear... (Score:5, Interesting)
Picked up Linux on the Mainframe [barnesandnoble.com] over the weekend, but plan to read it on a (very long) plane ride next week - looked like it focused on care and feeding, however.
not cost efffective (Score:5, Informative)
1. for the equivalent # of VM's it was more cost effective to buy new Intel hardware. The annual maintaince cost for the IBM more than paid for all new hardware.
2. Software availability. The only thing you could run it would be home grown apps or existing opensource apps. No commercial software was available. This company was an all Oracle shop, no DB2. They're primary opensystems backup solution was Netbackup. Which at the time had no client for linux on Z. (a year ago).
3. In house expertise. They had no linux expertise and very little Unix (solaris & HP) (jr admins at best) expertise. Let alone running linux on a Z.
So to sum it up. It's a very expensive, somewhat propritary and inflexiable environment. If you have a specialized use for it and can justify the cost go for it. Otherwise stick with commodity Intel/AMD hardware. It'll be cheaper and easier in the long run.
Re:not cost efffective (Score:5, Informative)
BTW - I've ported a number of programs to Linux/390 (an IBM G6 mainframe) and compared them to Linux on my 1 GHz Athlon cobbled together from left over parts and a motherboard from Fry's. The net result is that the Athlon is about twice as fast as the G6 mainframe.
The latest and greatest mainframes are about twice as fast as a G6, but PCs have come a long way since 1 GHz. Currently, 1 CPU on a mainframe running Linux costs about $100K, you can buy a pretty impressive Intel server for that price.
So, Linux on S/390 is only effective when you have a bunch of machines with utilization close to zero - let's call it "epsilon", which is what we mathematicians say when we really want to say zero but still need to divide by it. You buy the box for VM, which can run hundreds or even thousands of instances, securely and stably, so long as most of them are doing nothing.
Linux/390 is great for experimental servers, test systems, etc. OTOH - if you have any significant workload, buy a rack-mount PC.
Alan.
Re:not cost efffective (Score:4, Insightful)
Linux/390 is great for experimental servers, test systems, etc. OTOH - if you have any significant workload, buy a rack-mount PC.
Re:not cost efffective (Score:3, Insightful)
Management costs for dedicated servers which are almost idle, but still required as dedicated servers for many reasons are high. Also, reliability is an issue when you suddenly multiply low cost servers, which in turn reflects on the management costs, hardware cost and downtime cost.
Re:not cost efffective (Score:3, Informative)
It all comes down to crunching the numbers. I think IBM is actually pretty honest about z/Linux, they're not trying to sell it as a supercomputer but rather as a consolidation solutions.
FWIW - I work for a very large company with thousands of servers. We have dozens of them with utilization of approximate
Re:not cost efffective (Score:3, Insightful)
That depends on your definition of speed.
Mainframes aren't bought for raw MIPS.
Re:not cost efffective (Score:2)
Re:not cost efffective (Score:4, Informative)
A mainframe is not a supercomputer - the former is build for I/O, the latter for processing speed. There's a little overlap, but they address different markets - the workload for commercial data processing (for example, updating the accounts of your 10M customers with 100M transactions a day) and scientific number crunching (say, modelling a weather front). An IBM mainframe is designed from the ground up for I/O speed, and has dedicated processors that do nothing but shuffle data from storage to memory and back again. You cannot buy an Intel based system that even comes close to a Z series for I/O at any price. Even clustering Intel boxes won't help, because at some point, you have to have something to manage and consolidate all that data so you can do useful things with it. If you need it, there simply is no substitute for a mainframe. But if you don't, I agree that a mainframe is overpriced, just like a tank is overpriced if you just want to drive to the supermarket.
Re:not cost efffective (Score:5, Informative)
Re:not cost efffective (Score:2)
Re:not cost efffective (Score:3, Informative)
It is always a better choice to use clusters of hardware, than a single box.
You have a variety of tools available on the open source market now to monitor, and automagically maintain your cluster, depending on what you choose...the most popular is PVM, and it comes with a ton of very nice management utils you can get off the net, too manage hundreds of machines in a blink of an eye. This is a very configurable cluster architecture.
There is also MOSIX, or open Mosix. A very nice co
Re:not cost efffective (Score:2)
It also blatantly ignores that for a cluster, YOUR APPLICATION need to explicitly manage availability and reliability, or a single node can potentially take down everything if it fails, whereas a mainframe has extensive availability features built in. If you have a 16 node cluster,
Dunno about Z/Linux but... (Score:5, Interesting)
I haven't worked with a Z/Linux VM before. However, I have used User Mode Linux [sf.net] to create a dozen or so virtual servers per host server. And I'd imagine that the benefits offered by UML would also apply to Z/Linux VMs.
For example, with UML you're able to get much better resource utilisation. e.g. most of the time the machine is idle. When one of the UML servers need the host server's resources, they're there (CPU, network, disk IO, etc). That means you can have multiple UML servers bursting up to the performance potential of the host server. Certainly a better resource utilisation than having several host servers running mostly idle.
Another benefit of virtual machines are their logical separation from the host server. Each virtual server has their own users (including root), applications, file systems, IP address, etc. That means that if security is compromised on one, the others are unaffected. Ditto resources can be allocated to each virtual server according to need. And any mis-configuration on one doesn't affect the other. This compares to running multiple applications on the same server for different purposes (e.g. running HR and Account systems on one server, if email goes down them both systems are affected. In a virtual server setup, only one of the other would be affected.
So... Thumbs up to server virtualization software in general. Particular kudos to UML. And good luck finding out about Z/Linux!
- P
RimuHosting.com - Linux VPS Hosting [rimuhosting.com]
A little one-sided. Here's the downside of VMs (Score:5, Insightful)
Ahh yes, grasshopper, but when that one uber-box dies(hard disk, fan, power supply, whatever), gets powered off by accident, network cable unplugged, yadda yadda- it affects ALL the virtual machines.
Granted in the Big Iron, you've got lovely hot-swap capabilities and such(processors, memory, etc)...but nothing is foolproof or 100% reliable. It's the old joke with pilots about twin-engine airplanes; the door swings both ways and there's no such thing as a free lunch. On one hand, you've got a spare engine if one dies, but you're 2x as likely to have a failure, you've got a lot of added complexity, and sometimes it still won't save your bacon(twin engine planes have an abysmal survival rate for engine failure in part because of the really shitty way they fly with one engine down). This is VERY applicable- because managing this big IBM server is much more complex(the whole point of this article) than seperate hardware.
Best example I can think of in how hot-swap can still not save the bacon is with the Cisco PIX 5-something(The 1U pizza-box one). It has FULL failover- if you've got two, and one shits the bed COMPLETELY, the other one takes over absolutely everything, including active connections; they share ALL state information for what's called stateful failover. Aside from a momentary blip where things stop for a sec...nobody's the wiser that a piece of very expensive hardware just let the Magic Smoke out. The problem is that the PIX OS version we had was buggy and would crash randomly- and because they were sharing connection tables and everything, they'd BOTH die, which was REALLY bad since the boxes didn't have hardware watchdogs(!). We turned off fully-stateful failover, and the problem went away; we'd notice they'd ping-ponged(there's an 'ACTIVE' led to show you which is live) and we'd power-cycle the other.
So ask the tough questions; instead of asking what's N+1, ask what's NOT N+1, and do a very careful breakdown of what exactly it will cost to run this big huge box, and figure out what the 'per [virtual] machine' costs are...
Re:A little one-sided. Here's the downside of VMs (Score:5, Interesting)
Re:not completely true (Score:2, Insightful)
IBM Mainframes have the advantages of a very old and robust operating system, reliable and redundant hardware, and a thorough testing process before they are shipped out the door. This is what makes them more reliable.
Re:not completely true (Score:2)
The manager working with me on the project was mildly dyslexic and when explaining me the expected workload managed to convert one request every seven seconds to seven requests a second.
Two months later I am ready to test this thing, have created a special app that hits my engin
Re:A little one-sided. Here's the downside of VMs (Score:2)
Re:A little one-sided. Here's the downside of VMs (Score:2)
Do you need one license of Windows because it is all running on one machine, or do you need 11 licenses (one for the host operating system, and one per virtual machine) in order to be 'legit'?
I ask this because of the way XP Pro (and presumably Server 2003) is locked down and needs to be activated on a 'per machine' basis - this could be a very real iss
Another User-Mode Linux hosting service (Score:2, Informative)
Bytemark Hosting [bytemark-hosting.co.uk] offers Linux virtual machines via User-mode Linux.
Bytemark supports Open Source with contributions to Debian and discounts for Open Source developers.
Debian is one of the distro options. Primary DNS on Bytemark's DNS servers is included (running djbdns [tinydns.org], win win).
Re:Dunno about Z/Linux but... (Score:2)
www.vmware.com
I don't know if it is still under IBM's direct control or if VMware is a new company, but I am pretty sure that IBM is the original source.
Re:Dunno about Z/Linux but... (Score:2)
Z/Linux at a big financial firm (Score:5, Informative)
With careful planning, and the expectation that it will be a bumpy start, you'' find that it's a very rewarding experience, both personally and professionally.
Re:Z/Linux at a big financial firm (Score:5, Interesting)
This is a very, very, very important point to consider. If you let IBM run the whole shootin match from a distance, and something goes wrong, expect downtime.
This isn't related to Z/Linux but it is related to IBM and their systems management. At the business of my employment we outsourced all our network/systems administration to IBM. In the past 2 months (July and August) we have had not 1, not 2, but 4 very very major worm/virus infections that shut the entire network (as well as business) down. IBM didn't keep any systems up to date on patches (and the corporate security department didn't help either... they approved Win2k SP4 in an awful hurry after they found out it contained the Blaster worm fix) and told us to leave our unprotected computers on 24/7 and they would update them "in the next few days." I leave the determination of what happened after that as an excercise to the reader.
But hopefully IBM won't do that to your Z/Linux VM... Hopefully you'll have someone on site who knows their stuff, even if it has to be you (hey, then you can ask for a raise!)
No fears, IBM will take care of you (Score:5, Informative)
If you have problems, contact IBM and they will get their best people on it. IBM is all about customer service. You never get fired for buying IBM. From an engineers perspective, it's a pita. The best people in a department end up spending most of their time working on customer problems.
Hell, IBM still supports OS/2. If a Z-Series seems to solve your problem, go for it. IBM will take care of you.
Re:No fears, IBM will take care of you (Score:2)
Linuxcare? (Score:5, Informative)
http://www.linuxcare.com/ [linuxcare.com]
Chrisd
Ahhh, IBM... (Score:2, Flamebait)
Re:Ahhh, IBM... (Score:2)
Most people here have probably put together a cheap linux box out of spare parts and the like, such a box is great for a lot of uses, but do you want to trust your corpate servers to it? I don't. There are different types of things for different reasons. IBM makes it their goal to sell the high end high bandwidth high reliabilty stuff, and yes its high price but
It works well (Score:5, Interesting)
I sold and installed the very first Linux application on the S/390 --a Multiprise running VM and it worked great. We used the TurboLinux port and then finally wound up with SuSE.
We compiled the source code and it ran just like it did on a big Intel box. IBM helped with hardware issues which related to load balancing amongst the VM instances. One of their business partners supported the customer, Winnebago Industries with regard to Linux and OS 390.
IBM wasn't much of a factor as far as needing support. They supported the mainframe, the OS and VM just fine. SuSE installed without a single issue.
Some other issues arose in getting the user to learn IBM mainframe lingo, such as IPL instead of boot, and DASD. But, that didn't require much effort. The IBM Redbook on running Linux on the S/390 was all we needed to transfer knowledge. We downloaded it for free in pdf format.
The main benefit I discovered was the ability to consolidate servers. We replaced a bunch of M$ Exchange servers and ran a suite of Open Source apps such as Cyrus IMAP, Open LDAP, Exim, Apache, etc. We were able to get rid of a bunch of distributed servers and put them on one instance.
I suggest that IBM can help, but I don't think you'll be dependent on them. They're very expensive. With Linux on the zSeries or S/390 you can do everything yourself. -- That might not be what IBM wanted, but then they championed Linux, didn't they!
Re:It works well (Score:5, Interesting)
With Linux on the zSeries or S/390 you can do everything yourself. -- That might not be what IBM wanted, but then they championed Linux, didn't they!
Oh, I think IBM will be just fine with that. Sure, they want to sell services, but selling mainframes is also a lucrative business -- more lucrative than services, in terms of gross margin. Whether you need their services or not, they're getting paid. Even if you already have the mainframe and don't need to buy one for the project, eventually you'll fill it up and need more power. They'll wait.
IBM understands the value of long-term client relationships; they'll ultimately get a lot more of your money if they don't try to take it all now. What's really interesting about IBM is that they've now learned that they'll ultimately get a lot more of your money if they make it easy for you to buy elsewhere.
See, if customers feel trapped, they'll often willingly suffer short term pain so that they can avoid being caged forever. IBM has realized that if they give the customer open solutions, (a) they gain a short term competitive advantage over closed solutions and (b) they make customers comfortable, happy and trusting. Then, as long as all of IBM's offerings are reasonably competitive, the simplicity and convenience of having a single IT vendor will allow them to paint the customer's entire infrastructure Blue, while the customer sits serene in the knowledge that if needed they can always go elsewhere. IBM, of course, will try to ensure that the customer never feels that need.
IBM's ultimate goal in every client relationship is simple: They want to get to the point where whenever anything is needed, the CIO's first move is to call his IBM client rep. Or, even better, for the client rep to pick up on the CIO's frustrations and point out the need, and IBM's solution, during their twice-weekly lunches, or when they're golfing, or having a barbecue at one or the other's home. To achieve that, it's not necessary that buying IBM always be the best idea, only that it's the easiest idea and that it's *never* an egregiously bad idea.
This works, and it's a strategy that's completely out of reach of every IBM competitor because none of them have the size to pull it off. Well, HP might have the size, but lacks the breadth and the customer focus, at least so far.
So, in your case, IBM is just fine with it, because even if you didn't buy the services this time, you're an "IBM Shop", and you're happy. Some day when a new project comes up and your staff is just tapped out, or when a new technology comes along and you don't have time to understand or deal with it, the happy Blue glow that emanates from the smoothly-running z-Series will convince you to call IBM and "just let them handle it". And handle it they will, with a 30-40% profit margin.
Re:It works well (Score:2, Informative)
"Keep the customer satisfied" works for me. They know you can go elsewhere so they try very hard to get you not to need to, nor want to.
My favourite analogy is that of European and American Roulette wheels, US wheels have a double zero and European ones don't. They'll likely both get the same money but the US ones want it quicker. (Of course all analogies are flawed, and this one ignores effectively free food and drink at US casinos...)
zLinux admins need VM skills (Score:5, Informative)
Familiarity with Linux will not help you setting up the zLinux environment. It works like this: You dedicate a few processors of your mainframe to Linux. These processors will run VM, which has:
The users are defined in a "user directory". There, you can specify how much memory, disk and CPU share you want to give to each user. These users, remember, are in fact virtual machines that will boot an image of Linux compiled for the zSeries processor architecture.
If you want to create and take down Linux images frequenlty, you'll have to install and customize some VM scripts that will do the job for you. When the scripts are installed, you can setup a new Linux image (complete with its own disks, IP address, etc.) with a single operator command.
Most sysadmins of a zLinux machine spend a lot of time in VM. So learning VM is essential if you are going to do this job. VM was created 30 years ago and is somewhat primitive in places, but the resource virtualization mechanism is incredibly powerful and makes up for it.
Finally, make sure that people understand that there might be dozens of virtual CPUs defined under VM but only a few real CPUs. If you have 4 CPUs, a Linux user with an absolute CPU share of 25% will have the equivalent of one CPU. If the Linux image is used for recompiling its kernel, it might be a tad slow. The mainframe has great I/O performance but only run-of-the-mill raw CPU speed.
Good luck.
Re:zLinux admins need VM skills (Score:3, Informative)
Nobody said the contr
Avoid misunderstandings... (Score:5, Interesting)
The key is for people to realize that the type of workload is critical when deciding to try zLinux, and any barking about Athlon vs. G6 is useless. Also, vendors need to realize that once you compile an app on Linux on any one platform, you're usually a recompile away from running it under Linux on any other platform. Hence my reasoning that any complaints about software availability from a year ago is also useless. More apps are being ported to zLinux everyday.
Linux on Z has a role, it just needs to be explored by more brave souls. Besides, I've always said that if I leave the company, I'd like to create an "ISP in a box" using a z800 and some ESS disk to host a few thousand virtual web servers. I implore people to please visit Linux@IBM [ibm.com] for more information.
Re:Avoid misunderstandings... (Score:2)
1. It's open source so we can sell, totally support, and patch the hell out of something we didn't have to develop or buy in the first place.
2. It runs on, what, over 20 different platforms and environments. If Linux helped Intel starve the midrange market, Dell might've closed in on us and HP in server sales in units moved. Instead, Linux helps us and HP move more systems in all of our product lines and continue to crush Dell. And HP d
Re:Avoid misunderstandings... (Score:2)
This is totally hypothetical, but as a VMware user I am curious : how do the virtual machines presented on the Z compare to the VMware VMs on an Intel box?
Can you migrate the VM images back and forth between platforms?
Will the VMs on Z also support all the other platforms that run on VMware on an Intel machine?
The reason I ask is that once the hardware has been virtualized it doesn't matter what the back end is, in theory, and I
lead balloon filled with hot air (Score:5, Interesting)
When the VSE instance bombs out for some reason, and we get effectively 100% of the CPU it responds like a pentium... maybe. Think P166.
Unfortunately in our circumstance we can't 'turn on' more MIPS because then our VSE instance is running on a 'bigger' machine and we end up doubling our licesing costs. Other alternative is to turn on the ILF (integrated linux facility) which dedicates 120Mips to linux only, without affecting other licesning, but that costs $150k. You can buy a lot of 2-way or 4-way pentium boxes with decent RAID arrays and get much better performance for that kind of money.
So if your shop is run by some sort of morons and you've got 100's of spare MIPS to burn, then Linux on the mainframe probably makes some sense. Otherwise, just get some intel boxes. Any savings the mainframe provides in terms of power, cooling, and ligher administration is going to be offset by massive complexity, poor performance, and a lack of easy support for a bizarre platform that few developers have access to.
Re:lead balloon filled with hot air (Score:2)
We prefer the term 'consultant'.
Given IBM's history (Score:3)
I have played with other OS's running under VM. IBM knows what they are doing in that field.
Combine the two, and I think you have something that should work well. However, I'd weigh the costs. I would think it would a good thing to do if you already have a z-box laying around that has some space cycles. However, I would think that a stack of Dell's or something would be cheaper than buying the IBM equipment.
oh my god, I finally have important information (Score:4, Interesting)
They're great number crunchers, but they don't hold up under any kind of pressure as a web server. We had the z-series with no sites on it run benchmarks and compare to our development box with 20 sites hosted, and the development box (Penguin Computing) kicked its ASS.
Every time one of our developers has to ssh into the IBM machine, they yell "Cover me, I'm going in". Our running gag is, if they're not done editing the apache config or whatever in ten minutes, we'll have to send in a rescue team.
My rational, scientific, carefully measured opinion is that the IBM z-series SUCKS. HARD.
Gee, I sure wish I wouldn't get in trouble for sharing our benchmark data with you. Oh well, you'll have to take my word for it and hope the majority agrees.
Re:oh my god, I finally have important information (Score:2, Insightful)
You clearly have no idea what you're talking about. Great number crunchers? I can't even imagine what your testing was.
Don't do number crunching on zSeries, you fool! (Score:4, Informative)
Covener, you're right. zSeries suck as number crunchers. They are great at intensive I/O jobs. They are great at consolidating servers that aren't all busy at the same time. But "brute-force an RSA key" is exactly what you don't want to spend your expensive MIPS for.
BTW, I found that on a web server mettle test, large file transfer performance was better on zSeries than on RISC boxes. The larger the files, the more advantage to the mainframe. This is an interesting side-effect of having processors dedicated to I/O and freaking huge I/O bandwidth.
Unless you want real mainframe class hardware. (Score:3, Insightful)
Coz for x86 servers, you can always use vmware e.g. vmware esx.
Not sure if vmware has anything lined up for opteron, but if that goes fine then it'll be cool.
Sticker Shock (Score:5, Interesting)
VM is expensive. Engines on the mainframe are expensive, and are the weak point in Z/Linux. Mainframes normally run batch types of workloads, and have great big fat I/O. They're not necessarily great processing powerhouses.
You can download Linux and install it on the mainframe; but you get zero support. If you want support, open up that big old budget again. When we looked at it, Suse wanted about $20k per year, and RedHat wanted $24k. We flew solo instead. So far it's been fine; but be prepared to pay if you want support (which, by the way, is something the PHB's and mainframe systems programmers are used to having.)
As for operational considerations, I haven't really had any problems with it at all. There aren't many rpms out there for z/os; but you can compile almost anything and use it.
Installation is kind of cheesy; but not horrible. You basically set up your vm guest, log in to it and ftp the linux kernel, ramdisk and parmfile to the guest dasd, giving it a fixed record length of 80 bytes. You then feed these into a virtual card punch (that's right, a virtual Hollerith Punch Card Reader - 80 columns = 80 bytes), then into a virtual card reader, and ipl the reader.
This gives you a running instance of linux that you can use to do a net install of the full distribution.
In the implementation class I took, I was partnered with a mainframe guy who was complaining about how archaic vi was. It made me laugh.
"Dude. We just chopped my kernel into 80 byte blocks and fed it into a card reader. Don't talk to me about archaic."
Re:Sticker Shock (Score:3)
This is being done right now with VMWare also (Score:4, Interesting)
This really isnt a new concept, most of us know of the IBM P-series, Sun E-10ks and 15ks, and the HP Superdome. All use virtualization in one form or another to provide this kind of setup. Z/series is kind of novel, because....hey...its a Mainframe.
an idea... (Score:3, Interesting)
Re:an idea... (Score:2)
*warning* I work for IBM (Score:5, Informative)
I second the idea that it is very important to have VM skills on site for a customer looking at this. Presumably the customer is already a z/Series account, so they probably already know a thing or two, but they may have bought into the "VM is going away" speech and gotten rid of their VM stuff years ago and gone to z/OS.
Even if they have VM skills from 5-7 years ago - that will still do. VM hasn't changed all that much, it just has some more bells and whistles. So one or two refresher courses for whoever is still around in their shop will get them up to speed on z/VM 4.4 if they knew it 'Back in the day'.
And yes - Linux on VM is still young. Most shops appear to do a lot of 'roll your own' solutions to the administrative problems. Get hooked into the Marist linux390 mailing list, there are a lot of smart folks there who have at least thought about any problem youre likely to have.
I've run/tested every one of SLES 7, 8, RedHat 7.1, 7.2, RHEL3 beta, TurboLinux (old and crusty now) and Debian with pretty much any IBM middleware you could think of. From the linux side - it doesn't know anything about VM, or care. So you as the administrator must make sure it plays politely with the others it lives with. You probably should not just throw 2 Gigabytes of storage at it just because Websphere says it needs it. Running Linux with VM does require some understanding of how to make the most of shared resources. Check out this redbook:
http://publib-b.boulder.ibm.com/Redbooks.nsf/Re
It makes a lot of these points better than I can.
--Anonymous Coward cause I forgot my password
Experience with z/Linux and VM (Score:3, Informative)
As with anything, "it depends." In my experience, L/390 under z/VM works best in I/O-intensive heavy-throughput roles. Do not throw CPU-intensive work at it. If you need CPU, either build an Intel farm, or use an architecture that's designed for serious computing, like a pSeries.
From a manageability standpoint, you will be flabbergasted how much easier it is to manage a z/VM box with 100 Linux instances on it than it is to maintain 100 rackmounted x86 boxes. And once you get your legs under you with VM, it's amazing how tunable the system parameters are. FCON/ESA (now Performance Toolkit, in z/VM 4.4) is really, really your friend in terms of determining where the system hotspots are. And once you've tasted how to deploy additional servers in two minutes without leaving your chair, it's really hard to go back to old-skool provisioning.
Adam
Re:Experience with z/Linux and VM (Score:2)
I can see that installation of a virtual machine sure is a lot easier than plugging in a physical one.
But presumably each of these 100 linux instances has to be upgraded, managed, patched, etc. separately? So why is management easier under VM? Either way I'm going to be sitting at my desk logging into 100 linux instances.
Re:Experience with z/Linux and VM (Score:2, Interesting)
There's also the fact that with some basic scripting and use of some nifty open source tools (and the insanely fast inter-VM "networking") you can maintain one box, and all the rest just fall into line according to the frequency of your cronjobs. If you need to reboot, well, that's darn quick too, and requires zero r
Re:Experience with z/Linux and VM (Score:4, Insightful)
And - that restart command can be issued from a VM service machine (PROP - the programmable operator) whose sole function is to issue commands to all the Linux machines and make sure they do it.
So basically it's rpm -Fvh foo.rpm on the master disk image, followed by a RESTART FOO message to PROP and you're done.
(Note - I'm not Adam - but I can vouch that he does know what he's talking about and this is my guess at what he'd say)
Obligatory "slash" joke... (Score:3, Funny)
One thing.. (Score:2, Interesting)
I know IBM (Score:3, Interesting)
I still won't claim to be an expert, but given my background with IBM I would have to say that if they are recommending it, then it's probably the worst thing you can possibly do. IMO, they experiment on their customers. At least they did on me. The worst part is that my experience shows they are not very adept at getting people to help you through problems. They'll send somebody in who's read the manual and he'll hack around for a few days before calling in the real guy.
Its worse elsewhere... (Score:4, Interesting)
Kinda suprised (Score:3, Interesting)
Reading this sort of shocked me... in the past I worked for a major Canadian trust company ( hint hint ) and contracted to a different major Canadian bank, and both were in bed with IBM. In all honesty, im a bit shocked you have any say in the matter at all! From what I found of the IT departments at both banks... if IBM said it was right... it was right. Hell... I was hired to port a bunch of Visual Age C++ Framework ( forget the name now, but it was IBM's equivelant to MFC but on OS/2 and windows )to a Java compatible object model... so that eventually all their systems could be ported to java. If you remember a few years back ( perhaps 5 ) IBM was the biggest supporter of Java outside of Sun. Before that it was OS2, and for a while there I believe it was smalltalk ( before my time... ). Now, IBM has attached itself to Linux, and will consult all of their major customers to do this migration as well. Thing is... both the companies I worked with did what IBM said, almost blindly... hell, as far as I understand it, they are still porting away from OS/2 to this date... Poor bastards... im glad I left that world behind.
I guess the old adage is true... you never get fired for choosing IBM. You get a good look at the politics within a bank though... and you will see thats where most managers interests lay... self preservation... not doing whats right. Whats the Moral? Hmmm.... I suppose its just that, you should consider yourself lucky, that the financial institute you are work with even questions IBM's judgement
As to the VM solution itself, I have to admit, that particular technology I have had no direct experience with. However, unless you have the budget to have a complete server for backup ( as in standby, not as in storage... ) I dont like the concept in general. If you cant hot swap a server in place of the Z, you are playing with fire putting all your eggs in one basket. I dont care how many redunandcies are built in... you are still running multiple important tasks of one box. If you do have a hot swapable backup... obviously your budget is bigger then mine
Re:Kinda suprised (Score:3, Insightful)
The Z-series supports taking CPUs out of comission for replacement without downtime. Same for RAM. Multiple hot-swappable SCSI controllers connected to a fully redundant storage system such as the ESS/Shark (where you can connect to two separate banks of controllers, so tha
For God's sake, someone say it! (Score:3, Funny)
depends upon your problem (Score:2)
if you have a solution that requires heavy compute, low-to-medium I/O, no large shared memory ( unless you cough up the money for Myrinet, SCI, or Quadrics ) go with a Linux cluster using x86, x86-64, or (shudder) Itanium2 CPUs.
if you need a high throughput environment w/ fairly good compute, shared memory or not, go w/ a large UNIX machine, like an SGI Altix or Origin 3000, IBM Power 4+ box, HP Superdome ( or whatever they're calling them
-1: Slashdotism (Score:3, Funny)
You'll sleep better .... (Score:2, Insightful)
Re:No. (Score:5, Interesting)
I was impressed.
SG
Re:No. (Score:2, Interesting)
Re:No. (Score:2)
Re:No. (Score:3, Informative)
TurboLinux, yes (Score:3, Insightful)
Re:Doesn't seem like such a big deal (Score:5, Informative)
Re:Doesn't seem like such a big deal (Score:3, Insightful)
Re:Doesn't seem like such a big deal (Score:4, Informative)
Not quite, though the effect is similar. Both VM and Linux are supported by a combination of software and microcode. However, IBM has been very successful in putting almost all performance critical code sections in microcode. Thus, VM and Linux are 'emulated', but the overall performance usually ends up being quite close to what could be achieved if the support was indeed natively supported.
Re:Doesn't seem like such a big deal (Score:3, Funny)
You do realize that emulating any decrepit UNIX machine must be a rusult of running ancient code that has now been copied into SCO Unixware. You would then be using SCO IP (Idiotic Property). You will have to pay them 100 trillion dollars plus $699 for the Linux.
nah (Score:2)