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?"
Re:No. (Score:5, Interesting)
I was impressed.
SG
Re:No. (Score:2, Interesting)
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.
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]
CMS not Linux (Score:-1, Interesting)
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!
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.
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.
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:A little one-sided. Here's the downside of VMs (Score:5, Interesting)
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: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!)
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: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: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.
One thing.. (Score:2, Interesting)
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 remote power management (which also raises the MTBF, since power management always seems to fail at inconvenient and/or downright damaging times).
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:Water cooling? (Score:3, Interesting)
Later crays cooled themselves by using a liquid containing man made blood plasma that is used in blood transfusions.