IBM Promises Logical Volume Management For Linux 195
An Anonymous Coward writes: "I found the following message posted to several Linux mailing lists:
Well, the message sounded interesting so I checked out their website. I found the specified white paper in the "Documents / White Papers" section. After giving it a quick read, I must say that this isn't like any other LVM I've ever heard of! The use of "plug-in modules" to control what devices the LVM sees, how it partitions those devices, and how it uses those partitions to create a volume is incredibly flexible. I also like the part about the LVM working with the filesystem on a volume so that a volume can be resized without any data loss (and without all of the manual steps that must currently be done on Linux). The paper discusses this LVM as an architecture, and it avoids discussing user interfaces and implementation issues. I wonder if this is some pie in the sky vision or if they have any code to back this up?"************************* Begin Message **************Hello! Since IBM has begun to publicly support Linux, many of our customers have started showing an interest in Linux. We have received many requests from our customers asking us to enhance certain areas of Linux (logical volume management in particular) in order to make Linux a more acceptable platform for their IT operations. Furthermore, we have been asked to provide a migration path from existing platforms (both IBM and non-IBM) to Linux. IBM has been moving to satisfy these requests by contributing developers and technology to the Linux Community. This is what drove IBM's decision to release JFS to the Linux Community, and it is driving the decision to release logical volume management technology to the Linux Community.
IBM is releasing one of its most advanced architectures for a Logical Volume Management System. This architecture is quite interesting as it completely integrates all disk and volume management into a single, highly extensible, easy to use entity. We hope that the release of this technology will lead to a world class logical volume management system for Linux, one which satisfies the requirements of our customers as well as those of the Linux Community.
The first of several white papers describing the LVMS architecture can be found at the IBM Linux Technology Center website:
Since we would like to have an honest, open discussion about this, I would suggest that all interested parties post their comments to the LVM mailing list (unless someone has a better suggestion!). All comments are welcome!
Thanks!
Ben Rafanello
IBM Linux Technology Center
PS - Information about the LVM mailing list can be found at:
***************** End Message *************************
What else? (Score:1)
It'll also be interesting to see how this works with the other Linux LVM (no link - sorry). Will we end up with a similar situation to the current journalled filesystem developments where we go from 0 journalled filesystems to 4 (ext3, reiserfs, XFS and JFS)?
Re:Sigh (Score:1)
Idiot.
--
Re:Ben Rafanello responds (Score:1)
Re:Linux already has an LVM (Score:1)
as far as duplication of effort, I guess you're right, I mean let's only develop one journaling file system also. Which is it going to be? Choices are good.
Re:Linux LVM (Score:1)
IBM is talking about taking their LVM and making it more modular. This is good progress. Take a company that had a good product. They like this product, but there is a Linux model that has some things they like. What do they do? They integrate those features into their product and release the source code.
I think what we are going to end up with here is the best of both worlds.
HUH? (Score:1)
what's your problem with lpr and postscript? Linux already uses both anyway.
Re:IBM does indeed "get it" (Score:1)
Be GPL (Score:1)
Think about it. Why is IBM doing Linux? Mindshare, pure and simple. It could cost them in the short run to create things without licensing fees (of course, they do get free developers from the hobbyists who want to join in), but, in the long run, they get the mindshare of everyone whose lives they made just a little bit better that didn't have to pay them for it. Having thousands of OS supporters and developers thinking "IBM is really cool" is an intangible benefit, but it could be worth a whole lot in the future.
I'm not sure if it's a corporate tactic, plain common sense, or pure kindness, but I think I can live with it.
Re:Can We Trust IBM? (Score:1)
include smit/smitty or something like that?
I hope not, I really do. smit/smitty are just wrappers (smit is tc/tkl) that exec the real commands anyway, I'd rather have the command lines with better documentation.
Now the new WebSM system would certainly be welcome... especially if they provided the WHOLE thing, instead of just the part for LVMS... that would put linuxconf and all the others into the "also ran" category in no time flat.
Re:Just say "No" to "logical volumes"... (Score:3)
LVs complicate system management; in particular, they make it more difficult to figure out what physical devices a file system actually depends on, and they make it much more likely that you make a mistake when setting up disks.
Not really, the LVM is always happy to tell you what maps to what, and this is not problem unless you create a logical root volume in which case you deserve what you get. Disks are too cheap these days for that sort of foolishness, and if you need LVM you can afford it.
LVs break the correspondence between block numbers and head positions. With simple physical mappings, small differences in block numbers usually correspond to small head movements, something file system designs tend to rely on, but with LVs, all bets are off.
What planet have you been living on, Mr. Jetson? The geometry the OS sees has had little or no relation to the physical geometry of the disk since disk controllers became more intelligent than the first PCs several years ago. Where things will actually land physically on modern disks has been totally out of your control for years, which is the reason Sun dropped the ability to twiddle cylinder groups way back in the move from SunOS to Solaris.
If you take advantage of LVs spanning multiple disks, you just multiplied your risk of data loss, because if any one of those disks goes, so does the whole file system.
That's why LVMs and RAID travel in packs - they form a symbiotic realtionship. With disks as cheap as they are, mnay people just use 0+1 (mirroring and striping), which eliminates this concern. If you're cheap and don't mind abysmal performance in degraded mode, you can go with 5.
If you need file systems bigger than a single disk, use RAID.
Have you ever done this? RAID tools that do this are inherently *doing* LVM, even if they're not calling it that and it's not a separate tool. RAID per se typically handles Mirroring, Striping and Parity, the volume manager handles concatenation. These are often merged in a single tool, but concatenation of disks is not strictly speaking a RAID function.
GNU Parted and PartitionMagic already provide you with the ability to resize partitions without a full backup and restore; you don't need LVMs for that.
While decent, these are hardly enterprise-class tools. I also sincerely doubt that either is capable of resizing volumes that span physical disks, since that *does* imply LVM functionality, unless there's an LVM hiding under the covers and lying to these tools. There are people that have a real need for single files that are tens or hundreds of gigabytes, so *not* spanning disks isn't really an option.
One of these days, Linux may get concatenated mounts, which would give you another, very reliable and simple way of having file systems span multiple disks. Adding concatenated mounts would probably not be any harder than hacking in an LVM.
I'll confess to being ignorant of concatenated mounts (although I asume this would allow simply allow concatenation at mount time, but LVMs have significant benefits, and the people who need them have been using them quite successfully for years. There's certainly noting that's going to prevent the need for them in the near term. LVMs make "big computing" possible on small computers. There's just no effective way around that.
LVMs may have thier shortcomings, and they aren't appropriate everywhere. Most people won't need them, and the ones that do can handle the minimal incremental complexity. Further, what are often called LVMs are usually today also RAID and JFS tools. This sort of capabilty is not easily duplicated in other ways or we'd have been doing it already for years.
It seems you really are living in Jetson-land as your ID indicates if you think things like "object based disk storage systems" are going to have large-scale real-world impacts anytime soon. Ah, the naivete of youth...
Re:Cool! Now, what about smit? (Score:2)
Smit was not bad as a text based admin tool (I found the X11 version very cumbersome). But the problem with it was that for many operations, it was, in fact, the only choice you had, because command line equivalents either didn't exist at all or were not well documented.
Another problem with AIX system management was that much of the configuration information went into a big binary database somewhere. That made it nearly impossible to manipulate that information from scripts. Furthermore, if AIX ran out of space while writing the system management database, the system would become unstable or unbootable.
What AIX has going for it is that it's a robust, stable system once it's running (in part, due to the hardware). But I don't think AIX system management is a good model for Linux to aim for. That's why they make all different kinds. If you like AIX or NT, they are widely available; I see no need to turn Linux into either of them.
Re:Linux LVM (Score:1)
Re:Can We Trust IBM? (Score:1)
Officially worded as: "IBM provides how-to and defect support for the four major distributions of the Linux OS: Red Hat Linux, Caldera OpenLinux, TurboLinux, and SuSE Linux."
It will be interesting to see... (Score:2)
Re:IBM and Linux (Score:1)
They certainly never considered putting their Single User, 286/386-specific, client OS on RS/6000s or AS/400s.
But anyway, like everyone else says, IBM "gets it" now. One thing they never got back in the OS/2 days is that it makes sense to promote PC-based servers. Maybe OS/2 missed the boat, but Linux fills the bill, especially since IBM now is willing to make tons of money of servicing and supporing other people's stuff.
Re:Can We Trust IBM? (Score:2)
I remember way back in the early AIX days discovering the hard way that S*IT didn't keep it's state in the config files, but in the ODB, so any changes you made by hand would be silently undone when S*IT realized the config file didn't match the ODB, forcing you to do nearly everything through S*IT if you wanted the changes to stick. AAAARGH!
Re:Can We Trust IBM? (Score:1)
Just do a search here on
Lets be honest here though, they are driven by market demand like any other company. It just so happens that right now, market demand is in line some of the needs of the open source community, so their giving back while making money.
Nothing wrong with that. Don't look a Big Blue gift horse in the mouth.
Re:Ben Rafanello responds (Score:1)
To answer your question, we have a method for associating drives. In a nutshell, we assign a unique ID to each drive in a machine. We then copy to each drive in the machine the ID of the drive that the system booted from (the BootID). When a drive is moved to a different system, the BootID on the travelling drive will not match the ID of the drive that the new machine actually booted from, thereby allowing the new machine to identify which drive is the travelling drive and resolve any conflicts in favor of its native drive. Of course, this scheme depends upon the how unique the IDs assigned to the drives really are ...
Does it resolve the conflict automatically? Or, more likely, does it ask the manager to pick up a new name?
Heck, I suppose it does both, it first resolve with a temporary name (like conflicting_name_2) and work with it while asking the manager to pick a new name.
Exactly!
Ben Rafanello
IBM Linux Technology Center
Re:Ben Rafanello responds (Score:1)
As I understand it, Block devices could not be used to simulate "Partition Managers". Currently, implementation of new partitioning schemes requires multiple components in the system to be modified.
2. On top of the block devices you can layer the RAID and LVM "features modules" which are then available transparently to upper layers.
As I understand it, there is no generic architecture or mechanism for doing this under Linux at the moment, and the existing mechanisms which can be used to get around this all have significant limitations or drawbacks.
Integration among those components may need some work but overall this does not seem that different.
When viewed from a sufficient distance, the two systems do not seem all that different. But as you get closer, you find that the devil is in the details ...
Providing a single administration point for the users is certainly something worthwile but that this is hardly something which could not be done with the current system.
True.
Finally, LVM (any flavour) do just provide a framework. A filesystem does not become resizable on its own.
Agreed.
Ben Rafanello
IBM Linux Technology Center
Re:Ben Rafanello responds (Score:1)
It's probably true, but the advantage of beginning from scratch is taht you are not encumbered by backward compatibility and therefore have more liberty in your design.
Why do you need too? (Score:1)
It even replicates the exact functionality of LVM for AIX and HPUX, from the opengroup.
Re:Just say "No" to "logical volumes"... (Score:2)
The whole point of LVM is to put more than one disk in a VG, so I don't get your comment at all. That *would* explain your problems with JFS, though, since any disk failure is guaranteed to take out your log volume!
If properly configured, all of these things work, and work well. That's why people use them!
It's always nice... (Score:1)
Re:Just say "No" to "logical volumes"... (Score:2)
Despite your worries that I'm a latcomer "IT boss", my slashdot ID is about 130,000 lower than yours, and I was a participant here for several years before I bothered to register at the advent of moderation. What *I've* seen Slashdot becoming over that time is a community that is increasingly populated by clueless newbies shooting their mouths off and a signal to noise ratio approaching zero. And yes, sometimes that ticks me off.
My comments weren't intended to be arrogant (sorry if that's what came across), but simply to inject some factual basis into the discussion where little existed previously. The reason I bothered to do this is that I've seen such little things lead to big misconceptions among the community in the past. I would hope that we all recognize that experience is the best teacher and those that have experience doing something can ofer a lot to those of us that haven't.
Re:OpenSource LVM already exists. (Score:1)
Re:Linux LVM (Score:1)
Why don't they just offer to work with the current LVM project?
Re:Linux LVM (Score:1)
Re:Linux LVM (Score:1)
Bureaucracy aside, I love Online JFS. Now if they could only get it to work on system partitions...
Re:Can We Trust IBM? (Score:1)
Re:The New IBM? I wonder. (Score:1)
"What, has IBM misplaced AIX, OS/390, or OS/400?"
For the purposes of this discussion they may as well have. This is an apples-and-oranges comparison, as I see it. I won't dispute IBM's continued donimance in mid-size to large computing installations. Linux is partly about that, but I am coming at this from a monetarily bigger point of view: the mass PC market. Linux may very well have a chance in that arena someday, where the systems you named likely never will.
Ah, the halcyon days of microchannel! There were several things right about the PS/2, aside from that. The Model 60 tower was the first PC I ever saw that required no tools at all to access and work on. I attribute their failure to (very) high prices, the floppy-based BIOS, and the poor decision not to release MCA to the world's hardware developers. My point is that IBM has the engineering to take over the PC market - the questions have been in marketing, timing, and image. This seems to me a good opportunity to improve on at least one of those factors. I don't think IBM has given up, even after the PS/2 and OS/2 marketplace debacles.
Re:Logical? (Score:1)
Haiku (Score:1)
Avert the predicament:
Root partition full
Re:IBM and Linux (Score:1)
Re:Just say "No" to "logical volumes"... (Score:1)
That's a relief.... (Score:3)
Re:Be GPL (Score:1)
Re:Just say "No" to "logical volumes"... (Score:1)
Linux LVM (Score:4)
Re:Can We Trust IBM? (Score:1)
Can We Trust IBM? (Score:3)
I'm just a bit leery (sp ?) of IBM cozying up with Linux and Apache. They may think everyone has forgotten how predatory they are but some of us haven't. I think most people see them as a MS foil and as a result consider them to be one of the good guys. Just remember, folks. 15 years ago, IBM was the oppressor of the tech industry. The only reason they aren't as powerful today is because they got too big and unresponsive, which led them to make several bad decisions.
Re:Can We Trust IBM? (Score:5)
That you feel IBM is less powerful today than the late 80's surprises me. By almost every indication financially the company is doing better and the general public (specifically the IT industry) has a more positive view of the company and not (I believe) for the reason you site. So IBM may not have a stranglehold on the tech industry lilke they used to, but that is "power" that they don't want. Look where it got them, and look where it is getting Microsoft.
As for bad decisions hurting IBM, they made their share of them. Their major mistake being their structural divisions of the company into different operating units in preparation for the governments forced breakup that never came. The ways in which they did this killed IBM in more ways than anyone not in the company at the time can even imagine. So even if Microsoft doesn't get divided, it could be very interesting anyway.
And I think that IBM's strategic movements towards Linux and other open source projects are much too broad and pervasive to be an IBM version of Microsoft's "embrace, extend, extinguish" that you believe it is.
Re:Linux LVM (Score:1)
Biting the Hand that Feeds You... (Score:5)
Besides Linux pure-plays like RedHat and VA Linux no company gets it more than IBM. Their contributions to Apache are impressive, they are releasing laptops with Linux, implementing a better JDK than Sun's for Linux plus they are behind the AlphaWorks site [ibm.com].But instead of thanking them or being grateful for their contributions certain people feel that they should bitch and moan about how IBM will turn on Open Source (how? By stealing GPLed code???). The tiff with Sun you describe is simply that IBM licenses some Java technologies but refused to pay Sun's exorbitant licensing fees for the J2EE brand. Wow, that is so evil, they implement a better version of Java than Sun then refuse to pay Sun for the permission to call it Enterprise Java.
Ingratitude is sad to witness.
Re:Linux LVM (Score:1)
This is false. You mix up filesystem and LVM. LVM is a software layer between physical devices (physical volumes) and block device (logical volumes). The logical volume is growable and shrinkable. But wether you can grow a mounted partition or not depends on you FILESYSTEM. So it just depends on you ext2/ext3 filesystem.
On HPUX VxFS (also called JFS for jourmaling is growable, but I don't remember if it's shrinkable).
Re:Biting the Hand that Feeds You... (Score:1)
As for Sun not submitting Java to ISO: very good. Look at how C++ and other standards are dragging on. Once one of these international bureaucracies gets their hands on it, you can forget further evolution in a reasonable pace (and Java still needs evolution). Sun, with it's JCP, found the ideal compromise between making an open standard without fully loosing control, thus still being able to press for speedy improvements.
In fact that is one of the big advantages often touted towards MSFT: they can have fast evolution, simply by doing things themselves without having to go through lengthy ISO processes etc. The drawback is that it's no longer adhering to standards. JCP is the right compromise.
Maybe in 10 years time, when Java is 'finished' it is time to hand it over to ISO.
In the meantime, SUN is still investing a lot in Java and it's evolution. Why should big and rich companies like IBM not pay for the brand in order to support this? At least they have a real say in the JCP, not something that could be said of MSFT API's and products (for which they also would have to pay licensing fees).
I'm also very suspicous on IBM's commitment to Open Source. Why al this attention for Linux? What is behind it? Maybe they fear other open source products (like *BSD) that might really threaten their own products (AIX, Monterey) and try to kill those off by single sided attention for the weaker contestant.
Re:Can We Trust IBM? (Score:1)
They have always worked with open API's. Unlike most other companies that kept the specifications closed. They still do.
They want control over their own products, and especially don't want to hand it over to ISO/ANSI etc since when that happens, you can wait for 10 years for the next version of the spec (i.e. it is dead. just look at how C++ evolves since AT&T handed it over to ISO).
They don't want control to monopolize the industry, but because they feel that is the best way to create open standards, while preserving the possibility for further and speedy evolution and improvements.
Re:SMIT (Score:1)
Re:LVMS is /not/ LVM (Score:1)
The software engineers, designers managers I see dress very casualy. Shorts and sandals are common as well as t-shirts. I wear hawaii style polo shirts, ibm t-shirts with chip logos on them, a linux fund t-shirt, t-shirt I got on the Cindarella ballet by Ballet Austin etc. There are two pool tables in our building in the cafeteria area, and there is a salsa/chips/coke/beer 'social meeting' on Fridays. It would be ackward playing pool and drinking beer in a stiff white shirt/suit isn't it!?
The work time is flexible. I am expected to call in if I do not get in by 10a.m. for some reason.
(And I can work from home. While I am writing this I wait for a run to finish.)
But to be honest I have to add that these weeks there is a lot of work to be done (deadlines) and so I did not get to the recently installed pool tables yet.
We develop our software to run on linux as well. (Oh, and some of us thinks it is important to use >1 compilers for development and write portable (endiannes, 32/64 bit 'resistant') code. Beside xlC I normally use gcc with all warnings on and treated as errors, well, ok, since it is not enforced I forget this sometimes...
Matyas
Linux on AS/400 (Score:1)
Cheers,
Simon B.
Re:Can We Trust IBM? (Score:1)
Re:Cool! Now, what about smit? (Score:1)
(Yes I know readlin is GPL'd, but surely that doesn't stop them writing their own version ?)
Re:LVMS is /not/ LVM (Score:1)
At any rate, IBM is doing some awesome things. They seem to be leading the way in HD technology. I've got a 6.4 gig UDMA drive that I need to upgrade to a bigger one and I'll definitely go with another IBM.
-core
EBSDIC... (Score:1)
Cheers,
Simon B.
Bah! (Score:2)
That lasted for all of a couple of years after I signed on with them. Several factors contributed to the decline of OS/2, including the internal infighting that you mention. And of course Microsoft was always happy to give the knife an extra twist at every chance.
I suspect a lot of IBMers are taking some pleasure in the hurts Linux is putting on Microsoft. I'm sure they're enjoying establishing Linux as a good solid leader in the features race, too.
Re:Cool! Now, what about smit? (Score:1)
Re:Cool! Now, what about smit? (Score:2)
Re:Logical? (Score:1)
Good ole Slashdot works like a charm (Score:1)
Already a good LVM for Linux (Score:1)
http://linux.msede.com/lvm/
Also, and LVM HowTo is available at http://www.linuxdoc.org/HOWTO/LVM-HOWTO.html
I'll be good to see another implementation though. More choices.
I run the LVM on my server with the 2.3.99-pre8 kernel and it seems to work rather well.
Re:OpenSource LVM already exists. (Score:1)
I'm glad I didn't follow Slashdot SOP and accuse IBM of hubris, misdeeds, or ignorance...
Maybe this will see the EXPERIMENTAL light of day in early 2.4 revs.
Jeremiah
The New IBM? I wonder. (Score:1)
If IBM is more flexible and courageous (yes, it takes courage to bring something like this project to your boss, knowing that it's going to cost a lot of time and money and you have no real plan to directly recoup those funds), we have Microsoft to thank. IBM's "new attitude" is definitely that of a hungry company, which is the opposite of what they were when Bill & Co. basically cheated them out of the financial windfall that was DOS, and then later out of Windows.
It's fair to ask yourself whether IBM would be bothering with Linux if they had a successful OS that they had developed in-house. Moreover, I don't think it's unfair to wonder whether this isn't a first move at proprietizing an IBM Linux, which might not be a bad thing in itself but this is a huge corporation and I, for one, have a difficult time believing they got that way and stayed that way through altruism. This is a Predator as dangerous as Microsoft, maybe more so since they aren't watched like MS is.
Maybe I am being overly skeptical?
Re: Looks like parts of AIX (Score:1)
It works fairly well, but I've only used it up to around 15 gigs.
I've got 90 drives and just over 970 gig of data under the AIX's logical volume manager. It is rock solid and a dream when dealing with with that much storage.
My company is pretty evenly split between Sun and IBM (though we're phasing out Sun as we upgrade) right now. I've used the semi-Sun product Veritas to work with the 1.1 TB we have running under Sun. While I'll be the first to conceed that the Veritas product looks pretty and for a novice might be easier to use, I don't feel it is as sturdy a product as AIX's LVM.
The downside to LVM is that it's utilitarian. Whereas Veritas has a pretty GUI that turns drives icons different colors depending on their state, LVM is text-based even when running under the GUI smit interface. That could be one of the reasons I prefer LVM.
Over the years, I've moved more and more stuff off AIX and Solaris and it has made sense. One of the prime reasons I haven't moved more is that Linux didn't have Oracle, a JFS or a good tool for managing large amounts of data. Oracle fell. JFS fell. Now I see LVM on the horizon.
If Linux keeps progressing at this rate, I'm going to have to start putting my data where my mouth is. There is soon to be no more 'if only Linux had {hesitation}, I'd move {service} and cut our costs by {huge figure}'. My {hesitations} are just about gone.
InitZero
Re:IBM continues to impress (Score:1)
Vermifax
Re:Forgot my format option (Score:1)
Vermifax
SMIT's not *that* inflexible (Score:2)
I'd agree that AIX adds a separate, proprietory binary configuration database (the ODM) to the UNIX flat-file configuration model, and I'd agree that the way in which the ODM is bolted-on to the UNIX model leaves some ugliness at the boundaries.
However, to say "SMIT is the only choice" for configuration is somewhat misleading. One of SMIT's strengths is that *everything* is implemented via commands and scripts, under the covers. Indeed, it's fairly easy to extend SMIT itself to perform custom per-system administration tasks by adding menu / form definitions and the actions needed to implement to the ODM database (which is what SMIT reads to produce the menus, as well as being AIX's authoratitive source of config. data).
Result? Everything that can be done via SMIT can also be done direct from the command line. In AIX, most (but lamentably not all) commands that change flat-file configuration also "behind the scenes update the ODM also. For instance, the user configuration commands (mkuser, rmuser, lsuser etc) not only affect the filesystem directly (modifying /etc/passwd, /etc/group, /etc/security/passwd, home/ etc), but also update the ODM. Likewise for most of the the device configuration commands (certainly the common TCP/IP commands have this dual-mode operation).
/bin/ksh and set -o vi (Score:1)
Filename completion:
Press ESC \ after typing the unique portion of the file. (Note it will also go as far as the name is unique)
Scrolling:
Once you press ESC you are in vi command mode. Use j/k to scroll through command history and vi commands to edit the command line
Vermifax
Definitely good for the community... (Score:1)
Now they just need to reorganize some people out of the old development centers and into new ones. Encourage them to think in new ways in a new environment. Maybe up here in Boston, so I can work there. That way you can pay me for all the installing-linux-on-Thinkpads advice I give you people.
-jpowers
lslv -p logvolume (no text) (Score:1)
Vermifax
Re:Can We Trust IBM? (Score:1)
My understanding of filesystems is a little slim, but if this new thing of theirs does journaling, that's one step closer to being US military-ready. Big Bucks.
-jpowers
Re:Cool! Now, what about smit? (Score:1)
First thing's first: Real SMIT users use 'smitty' to tell smit to run in terminal mode. The X version is indeed cumbersome (though I admit I like the wee running man - he falls over if a command fails :).
SMIT actually does (almost) everything via commands that you can execute yourself, which limits it in some ways. However this is also its advantage: Rather than pressing ENTER to tell smit to execute that command you've just given it, press F6 instead. SMIT will now tell you the actual command line it was about to execute. You can take this command and type it yourself, or, more importantly you can stick it in a script. Linuxconf isn't able to do that in the same way as far as I'm aware, or at best it does it in terms of its UI, which isn't a good way to script things. Have you ever tried to script setting disk space quotas under Linux? Aarrgh!
The ODM (binary database) is indeed something of an issue, and something I'm always fretting about whenever I have to do system recovery on an AIX box. Though it's been scary in the past to note Linux people talking about an NT-style 'registry' (shudder). Probably the main thing we can do there is that if such a thing ever does eventuate, ensure that it is well documented at a central site somewhere, and provide good tools to manipulate it. In particular such tools must be small and stand-alone so that they can be run easily in recovery mode.
Some things about AIX I'm not keen on, for instance its price, its devel environment, and some of its 'non-standard' wrinkles. But I've been working with it for 6 years now and I can say in no uncertain terms that its disk handling (LVM and JFS), and its system adminstration (SMIT) are nothing short of stellar, especially if you have to maintain one of these things remotely.
I don't think I'd like to see SMIT verbatim in Linux, but LinuxConf could learn a lot from it.
As far as IBM and the open source community goes I'm pretty comfortable. IBM got whacked good in the 80s, and have pretty much played ball since. More important though is the fact that they've been slowly reshaping themselves into a total-service oriented organisation for some time now, where they can make their money from the services they provide more than the products. Linux slots into this strategy very well, don't you think?
If you go and look at their JFS subsite you'll see that they've been making very steady progress on it since they started - I've been monitoring it regularly and I think what they've acheived in the short time so far is actually pretty remarkable!
Re:Linux LVM (Score:1)
Re:Just say "No" to "logical volumes"... (Score:1)
These are often merged in a single tool, but concatenation of disks is not strictly speaking a RAID function.
This is wrong, in the begining, RAID was meant to concatenate disk sizes. Rendundant Array of Inexpensive Disks means that many small disks are cheaper than one big disk.
Then it came mirroring and RAID 5. there are references to this in: seagate [seagate.com] and DPT [dpt.com] web sites and in the SCSI linux howto.Re:Can we lay off the nazi bullshit??? (Score:1)
Because they seem capable of making the distinction between what you're talking about and their general organizational behavior over the course of decades before that war, which was evil in a different way. Yes, there was a Nazi Party back in Nietzche's day, and while they didn't slaughter Jews (and my kin the Gypsies), they still displyed the same weird organizational behaviors.
We discuss it because the motivation to enforce conformity seems to be something we Americans as a society can't shake, especially in the corporate sector, and any part of our society that easily compared to theirs needs to be watched very carefully.
As it's often said: "Never forget." It's easier to keep it in mind if you talk it out.
-jpowers
Re:Linux LVM (Score:2)
At first it looks like this doesn't work as SAM pukes when it is attempted. The trick is to resize the volume using the command line.
I suppose I should qualify the above by saying that resize == grow. If I recall correctly, shrinking a volume is verboten. I don't have the documentation to back it up, but I also believe that the LVM included with HP-UX is actually a licensed Veritas VxFS.
This is good news for Linux in the enterprise (Score:2)
Even though this technology obviously won't make it into the 2.4 release, it will dramatically strengthen Linux's enterprise capabilities when 2.6 ships, particularly when coupled with the journaling file system in that release. Flexible volume management is taken for granted by most commercial users today, and capable LVM functions in Linux will put its storage capabilities on par with almost every other operating system available.
Note, though, that regardless of the design of the LVM itself, there are some tricky issues that need to be resolved in the implementation with an actual file system. For example, it turns out that growing volumes is fairly straightforward, but shrinking them is much more difficult. The paper mentions that specific support is needed from the underlying file system to enable shrinking, so even with this "gift" from IBM, there is still a lot of work to be done to come up with a useable solution.
Re:Can We Trust IBM? (Score:2)
And Sun deserved such a fate. IBM made huge contributions to Java with the understanding that it would be standardized; instead, Sun abandons the standardization process and charges $$$ for work that was in significant part done by IBM.
IBM's our best hope for a widely-adopted non-proprietary Java. IBM needs to integrate mainframes, Windows machines, OS/2 machines, Linux machines, and more; an open Java is a critical component of their buisness strategy. Sun wants to make money selling the replacement for Windows -- closed Java is they way they expect to do that.
Steven E. Ehrbar
Re:OpenSource LVM already exists. (Score:3)
The same could be said of Linus and FreeBSD. I think we're all better off with competition, because Open Source competition benefits both projects.
--
JFS & other code out to dry (Score:3)
Their JFS (journalling file system) is a good example of this. released quite some time ago, no effort to port it to current versions on the kernel and no apparent discussion about that is going on.
The LVM could be similar. *IF* they had released the LVM last year and *IF* they had supported it with a reasonable amount of programming resources we might care (and I say this as a person who has used and *loved* IBM's LVM on AIX). On the other hand, if they just release the code but don't support the transition and don't make an active effort to participate in community development of it, who cares?
Contrast this to SGI who, for all of their failings as a company, are releasing code *and* supporting its inclusion into the kernel through active participation in the linux-kernel list, web sites and other mailing lists. I'd like to see IBM get on board in the same way.
Ben Rafanello responds (Score:5)
First the easy ones:
I wonder if this is some pie in the sky vision or if they have any code to back this up?"
Yes, we have code. IBM has a prototype of this LVMS on at least one of its platforms that I know of.
As long as it's released under a liscense like the GPL, we don't need to trust them
We are currently releasing the technology to the Linux Community. The current white paper provides a high level view of the basic architecture. As the architecture is discussed with the Linux Community, additional white papers will be produced to explain, in greater detail, various aspects of the architecture. Should things progress to the point where we are actually releasing code for some or all of it, then any code we release will be under the GPL.
Heinz Maulshagen and team have already written an LVM for Linux. This LVM is already in the 2.3.x series of kernels. What is IBM's reasoning for this duplication of effort? Might it not be more effective to assist in the current LVM implementation instead of bringing additional complexity? Or are there advantages in IBM's approach to logical volume management?
Heinz and his team have done an excellent job with their LVM. However, we feel that our design has some advantages, and that we are looking at the problem from a different perspective. Let me explain.
IBM's initial concept of a logical volume management system was not all that different from what we find in the Linux Community today. However, over the years, IBM's concept has evolved based upon input from our customers, as well as usability studies performed on our customer base. Our current concept of a logical volume management system integrates disk partitioning and management, bad block relocation, software RAID, encryption, filesystems, logical volume creation, deletion, and management, etc. into a single, coherent, open ended architecture. All of the components of this architecture communicate with the Logical Volume Manager, who co-ordinates their activities and handles all interactions with the user. The Logical Volume Manager is a single program with three interfaces: a command line interface, a text mode interface, and a graphical user interface. Thus, there is a single place for the user to turn to for any aspect of logical volume management. This makes logical volume management easier for the user to learn and use, and it reduces the chances for user error and data loss.
As an example of IBM's concept, lets examine the case where an encrypted volume is to be shrunk. We will assume that the user has already been through any authentication process which may be required to access the encrypted volume and has been granted full access. The user would start the LVM. The LVM would allow the user to select a volume. Once selected, the user would indicate that the volume should be shrunk. The LVM would examine the volume, find which features are in use on the volume (encryption, in this case), find what filesystem is in use on the volume, and then ask each feature that would be affected by the shrink if that feature can handle having the volume shrunk without data loss. If a feature indicates that it can NOT handle having the volume shrunk, then the LVM informs the user that the volume can NOT be shrunk without data loss. If all of the features indicate that they can handle having the volume shrunk, then the LVM would ask the filesystem on the volume how much the filesystem can be shrunk without data loss. If the filesystem indicates that it can't be shrunk without losing data, the LVM will inform the user appropriately. If the filesystem can be shrunk, it will indicate how much it can be shrunk before data loss begins. The LVM will then present this value to the user and allow the user to specify how much to shrink the volume by, limiting the user's choice to only those values that prevent data loss. Once the user has specified how much the volume is to be shrunk by, the LVM will then notify the filesystem to shrink itself. Once the filesystem is done shrinking itself, the LVM will notify the features on the volume that the volume is about to be shrunk. After this, the LVM will actually shrink the volume. Once the volume has been shrunk, the LVM will notify the features on the volume that the shrink has been completed. The filesystem will also be notified that the shrink has been completed. Once all of this has been completed, then the user will be notified that the volume has been successfully shrunk.
The above example is quick and dirty, and it leaves out quite a bit, but I hope it gives you an idea of what we are trying to accomplish. Basically, we are trying to bring together all of the various aspects of logical volume management into a single, cohesive, seamless entity. Furthermore, we are trying to do this in a way which is as flexible and expandable as possible. Consider the following:
The LVMS architecture uses logical disks. Logical disks are created and controlled by plug-in modules called "Device Managers". Thus, anything that can be made to appear as a logical disk through the use of a plug-in "Device Manager" module can be used by the LVMS. As an example, lets say we have a "Device Manager" plug-in which can access a Storage Area Network (SAN). By just adding this plug-in to an existing system, the LVMS would be able to allocate storage on a SAN, make it appear as a logical disk, and then use any of the LVM capabilities that could be used on a local disk. No code in the LVMS, existing plug-in modules, or LVM utilities needs to be modified or changed.
The LVMS Architecture uses logical partitions. Logical partitions are controlled by plug-in modules called "Partition Managers". If you wanted to access a drive that was partitioned for use with a Mac, you would just need a "Partition Manager" plug-in module that understands the partitioning scheme used by the Mac. No LVMS, existing plug-in module, or LVM utility needs to have its code changed. All that needs to be done is have the Mac "Partition Manager" plug-in added to the system.
The LVMS Architecture employs something we call "Feature Plug-ins". Feature Plug-ins control how logical partitions are combined into logical volumes, such as through drive linking, the various forms of mirroring, or software RAID. They can also be used to filter I/O to a volume, as would be the case for encryption. They can also be used to redirect I/O, as in the case of bad block relocation. Furthermore, Feature Plug-ins can be stacked to produce a volume, so that multiple Feature Plug-ins can be used on a single volume (encryption combined with software RAID and bad block relocation, for example). Every volume in the system can employ different Feature Plug-ins, and volumes which do use the same Feature Plug-ins can have them stacked differently. Thus, the user has an enourmous amount of flexibility. One final point to make here is that, since all of the plug-in modules communicate with the LVM, the LVM can coordinate their activities to ensure that the user doesn't do something which will result in the loss of data (at least without adequate warning).
Given all of the above, I hope everyone understands why we think the LVMS Architecture we are releasing has some advantages over other approaches.
Well, this post has gotten excessively long, and I apologize for that. I will try to address additional questions/comments/concerns later, hopefully with smaller posts!
Ben Rafanello
IBM Linux Technology Center
Re:LVMS is /not/ LVM (Score:2)
Not that this is not intended as a troll...I'm generally interested. I'll be graduating with a BS in CS in 2 years, and I'm trying to get a head start on job prospecting. As such, I don't want to work for a place that imposes arbitrary rules on work habits and the like.
IBM and Linux (Score:4)
Many IBMers expressed relief (on the IBM internal forums) that Linux was beyond the control of IBM, so the company couldn't screw it up the way they did with OS/2. Many of them are still bitter about that. Many of the old OS/2 guard have moved to Linux, happy to have an OS that lets them work the way they want to work.
I think it's cool that they're adding neat features to the OS. Having them contributing cool features why not trying to manage or market the OS seems to be the right way of doing things. Perhaps they should look at modifying their other business units to work in this sort of paradigm, with IBMers only contributing to projects managed by other business units...
Re:Can We Trust IBM? (Score:2)
However, some of this sounds a lot like the LVM for AIX - like expanding a volume's size on the fly. Wonder if they'll include smit/smitty or something like that? (Anybody else remember AT&T's FACE?)
carlos
OpenSource LVM already exists. (Score:3)
http://linux.msede.com/lvm/
Check Freshmeat for updates.
IBM would do well to work with the existing project, or at least to establish a good-faith basis for communucation with the developer community already committed to solutions under public license.
Jeremiah
Re:Can We Trust IBM? (Score:3)
This will be really good! (Score:2)
I just spent most of a day reorganising the partitions on several machines (backup, repartition, restore, repeat etc.). A LVM would have been an enormous help.
As for it's being ready or not; IBM don't usually make this kind of announcent unless they've pretty much gotten the technology down so I'd expect the project to be well on it's way.
Logical? (Score:4)
~# mount -t ext2 /dev/sda2 /home
Error: fuzzy dice in foo buffer found.
~# mount -t ext2 /dev/sda2 /home -o fuzzy_dice
Error: fuzzy dice requires car.o module
~# insmod car.o
Unresolved symbols: car_need_oil, car_need_gas
~# dd if=/dev/cash of=/dev/bank bs=1 count=300
0+300 records in
0+300 records out
~# dd if=/dev/bank of=/dev/wallet bs=1 count=50
0+50 records in
0+50 records out
~# insmod car.o io=/dev/wallet
~# mount -t ext2 /dev/sda2 /home -o fuzzy_dice
Succeeded.
~# cd /home
~# ls
KERNEL PANIC!
000:000 FF 00 CC G0 BB LE DE G0 0K
Goddamn illogical drives...
Re:Linux LVM (Score:2)
What I'd really hope is that IBM will license the code in such a way that the current LVM project could possibly use it to help the development.
IBM's work on releasing a port of jfs to the Linux community doesn't seem to have hurt the development of ReiserFS, ext3 or SGI's xfs. A little competition can often be a good thing.
Re:IBM is making good on promises... (Score:2)
I think that if IBM can clean up their act like they have, that maybe there is possibly some hope that Microsoft may someday decide that they don't have to play dirty tricks all the time too. I'm not all that optimistic that will happen any time soon, but I won't say it could never happen.
Unfortunately, for IBM it took a large scale turnover at the top levels of their management to get them to change their status quo. If anything, the replacement of Akers by Gerstner was the key turning point for IBM. Microsoft upper management is still firmly entrenched with Gates and his inner circle. As long as they stay where they are, it is unlikely they will change.
Re:Linux LVM (Score:2)
Re:JFS & other code out to dry (Score:3)
Cool! Now, what about smit? (Score:2)
If they do this, I hope they give Linux the tools to make the LVM usable. Particularly the mksysb command(can be configured to back up your root volume) and especially smit.
Smit is about the best sysadmin tool I've ever used. Its much better than linuxconf IMO. I know the purists out there think "a real sysadmin always uses the command line", however what smit gives you is the command line, in a convenient menu form. Rather than wading through the man page, you basically have a menu that comprises each command line option with a description of what it means. You can also hit F6 at any time to see the command you are about to execute. Which also makes it a great tool to learn Unix.
IBM is making good on promises... (Score:3)
In this article at ZDNET [zdnet.com], they talk about how IBM is releasing their Small Business Pack for Linux. They are trying to port more and more over to Linux. A lot of people don't seem to give them credit. I support this outright...and hope they release more stuff under a more flexible license like the GPL. I think that every corporation can see the light eventually. Here's to hoping.
Re:Can We Trust IBM? (Score:3)
I thought this was because Sun was charging licensing fees for thr EJB spec, and IBM didn't think that was fair. Thus, they register a protest by refusing to ratify it.
Re:It will be interesting to see... (Score:2)
Re:Just say "No" to "logical volumes"... (Score:2)
Support for LVMs, particularly the IBM one, if it is compatible with AIX could be important for Linux acceptance in the large enterprise market for that very reason. For that reason alone, I am happy to see IBM bring this to Linux.
Re:SMIT (Score:2)
Not surprising (Score:4)
Think about it. IBM sells a *wide* variety of products, from laptops to mainframes and from software to service. It complicates matters for them if they have to be "multilingual" with their platform systems; Linux gives them a way around this by, as suggested in the Halloween documents, treating the OS as basically a generic commodity.
The more popular Linux gets, and the better IBM's equipment works with it, the better their bottom line gets. If Linux gives them a platform to standardize around, then they can sell more hardware and support services and not have to worry as much about certain problems (compatibility, stability, etc) that live at the OS level. This is very much in their interest, but it's also in the interest of consumers as well, if Linux becomes a reliable system component along the lines of, say, a hard drive or a word processor. The consumer gets the benefit or a robust & rewarding system platform that works on most any equipment available; IBM gets the benefit of having their entire product range appeal to customers because it all speaks the lingua franca of the computer world that they are positively contributing to.
Consider EBCDIC. Wasn't that the standard text format on IBM machines back in the day? Is it in use on any modern system? [I'm asking -- not rhetorical...] It seems to me that they had the wisdom to (eventually) switch to the open ASCII standard before, and are promoting the new Linux standard now. I see no reason to be suspicious of this behavior -- everyone stands to benefit, or at least everyone that isn't trying to shill a proproetary in-house OS... :)
Just say "No" to "logical volumes"... (Score:5)
There are better solutions to the problem LVs are supposed to address:
IBM's LVM was one of the reasons I hated using AIX (they did similarly oddball and nonstandard stuff in some other areas). I consider it a poorly designed facility. While we can't keep people from porting stuff to Linux, I hope Linux distributions will not incorporate that kind of nonsense; Linux configuration and system management needs to get simpler, not more complex.
The drive for systems like LVM is understandable because UNIX and Linux file systems and large scale data management are not perfect. For example, a big ISP that runs out of disk space on some important partition and needs more space quickly has a legitimate problem. But rather than rushing to a half-baked solution like LVMs, let's identify what the problems are we really want to solve and come up with good solutions to them. With upcoming technologies like object-based disk storage systems, there seem to be much more straightforward and reliable answers than LVM.
Re:Linux LVM (Score:2)
Sorry, but this isn't true. I've been growing live file systems on DG/UX (data general) since 1994. A friend of mine working at a large Tru64 shop says that his file systems grow automatically as needed.
The IBM LVM news is great news.
LVMS is /not/ LVM (Score:5)
Let me tell you one of the neato things about working at IBM in Austin - I got to talk to Ben (yes, Ben Rafanello, the guy who posted the stuff to the linux mailing lists) all about this last night, and he told me he was planning on posting that stuff. So anyway, I read the LVMS whitepaper last night, and it is
For those of you who are wondering about what license it will be released under - well, I can't say for sure. Just remember that IBM GPL'd their JFS, and we continue to work on that here as well. (I'm actually working on the JFS here in Austin.)
And yes, IBM
-Will the Chill