fate of LVM

[Mark Henry_1]

All,

Does anyone know what the future of LVM on hpux is given the arrival of VxVM? Or, is there a plan to continue the two side-by-side indefinitely?

Thx,

Mark

[James R. Ferguson · Accepted solution]

Hi Mark:

Nothing lasts forever. Having said that, consider that at leasst as long as 11.i is supported, there would need to be LVM support. No date for the discontinence, let alone obsolence, of 11i is even on the horizon:

http://www.software.hp.com/HPUX-RDMP/history/slide2.html

I think you will see LVM coexist with VxVM for a long time, although certainly with newer O/S and servers, VxVM will become more prevalent.

Regards!

...JRF...

[Mark Henry_1]

James,

Thanks,

Do you know if VxVM was decided on as a complete replacement for LVM or just an alternative?
What was so compelling?

Thx,

Mark

[James R. Ferguson]

Hi (again) Mark:

My opinions are my own, and constitute educated guesses.

Consider that Veritas already provides the familar VxFS (JFS) module. Consider that VxVM exists and offers:

> A Java-based administrative GUI.
> Software based RAID-5.
> Dynamic multipathing for I/O load balancing (LVM alternate (pv) links do not. They are for failover/high-availability only).
> Support for up to 32 mirrors.
> Striped mirrors (whereas with LVM you choose stiping or distributed, mirrored extents, or kludge this yourself).

Thus, it makes sense to partner with and integrate support for a premium product. Afterall, why reinvent the wheel.

Have a look at some of the VxVM documentation. It is very interesting and very impressive:

http://docs.hp.com/hpux/onlinedocs/B7961-90021/B7961-90021.html

http://docs.hp.com/hpux/onlinedocs/B7961-90001/B7961-90001.html

http://docs.hp.com/hpux/onlinedocs/B7961-90002/B7961-90002.html

Regards!

...JRF...

[George C. Abraham_2]

Dear all

What is there so special about VxVm so as to completely replace our beloved LVM. I as so comfortable with LVM.. I belive LVM is there anly for HP. Why are they shifting?

[David Lodge]

I would think it is to support partnership deals or to save costs in reusing existing software, less development and support etc.

Personally I'd hate to see LVM go - To me LVM, though it isn't perfect is simple and flexible. VxVM is a wee bit more complex and the CLI is apalling...

IMO Having a Java GUI is a reason *not* to use VxVM :-)

dave

[Timothy Czarnik]

Mark,

I took the Veritas Foundation suite class a few months ago. From what I was told there, VxFS and LVM will coexist until HP-UX 11.20, after which time VxVS will be included in all core installs of HP-UX. I believe this was due to that fact that currently HP-UX must use a boot disk under LVM control.

The Veritas software command line was pretty scary, but the GUI I saw/used was VERY cool. It allowed for point/click volume group creation (disk group in Veritas speak), striping across different size disks in different locations, online logical volume resizing via GUI, and a number of other things.

The GUI kicks SAM's a$$ for performing disk space administration. Depending on how old you are, this can be a good or bad thing :)

-Tim

[Alan Riggs]

I think James gave a nice list of some advantages to VxVM. The java GUI, IMO, is by far the least important. Yes, the CLI structure for VxVM is more complex, but I think much of that stems from (un)familiarity. LVM is no more natively intuitive, it is just comfortable from long use. (And believe me, I am *very* comfortable with my broken in LVM).

A couple of things James did not mention:
VxVM has the ability to extend stripe sets dynamically. In LVM you must do a full data dump/reload to add a new disk to a stripe set.
VxVM is a standard interface that can be used "cross-platform", Already it allows a Sun/HP-UX admin to use a single command set for LVM work. As it becomes supported on more platforms (though I haven't seen any information for rollout on AIX, SCO, etc.) this becomes even more valuable.

[A. Clay Stephenson]

I think I will relate something that a VERY BIG DOG said this year at HpWorld. He said that it would be a very good thing to learn commands than start with vx. He specifically mentioned LVM and backup. After asking various people about the future of those products within HP the answers were 'not anytime soon but ...'.

Clay

[Bill McNAMARA_1]

there is no way I'm going to vx..

For a start lvm does what I want it to.

VxVM is expensive and a seperate licence per platform.
The GUI is not worth it.. load balancing will be brought in with lvm eventually.

There is around 500 vx commands with nasty options.

Software sucks to do raid 5.

Boot disks will always be lvm.
(try repairing a vxvm installation in rescue mode)

I could go on.. (but the list ends there)

[melvyn burnard]

And if you think all of the above is fun, try using VxVM in ServiceGuard :-}
as of 11.13 of SG.
scary is the word that springs to mind.

And of course another sub-forum for VxVM

[Frank Slootweg]

Well Bill, I surely don't want to force you to go to VxVM, but the standard/base version is bundled with HP-UX 11i. The full version is indeed extra cost. Since LVM and VxVM can co-exist on the same system, you can install the base version of VxVM to get a feel for it.

Frank Slootweg, HP.

[David Reno]

As a VERITAS employee, I guess I should chime in with the party line (not really).

Bill, it is interesting that you say that LVM will eventually include load balancing, do you have information to that effect? I doubt it, my understanding is that HP does not want to continue to invest in developing LVM any more than it wants to further develop file systems.

Yes, vx commands are many and options galore. However, we do have wizard command line utilities that can do things for you with very little knowledge of the full complexity of the command set. Also, having many options (as well as being confusing) is also flexible.

Software raid does suck compared to hardware raid, but can your hardware raid span arrays? No. Not only that, but maybe you have some old JBOD that doesn't support raid but you would like to continue getting some use out of it. That's what VxVM can do, give you a lot of options that you can add to your toolbox.

Boot disks will not always be lvm. We are working with HP to allow "rootability", as we call it. I think the slated release is HP-UX 11.21.

VxVM is certified to work with MC/SG 11.09. Not only that, but also Database Edition for Oracle and VERITAS Volume Replicator. VERITAS is committed to playing nicely with MC/SG.

HP-UX oriented sys admins are very loyal and focused on quality more than time to market. In my opinion, this is a good thing. Nonetheless, let's move the platform forward and keep it competitive (read: have an open mind to new ways of doing things!)

Since I am not a PR person (I am a systems engineer), I guess I should say that all of the above is only my opinion/understanding and is not a statement from VERITAS Software, Inc.

Best Regards,
David

[F.V. Porcella]

It looks like LVM will be with us for some time yet. VxVM has some very nice features, and a big price tag.

I have a question, What will happen to the 11.i Operating environments (Enterprise & Mission Critical) that contain Mirror/UX and JFS, when (and if) hp drops support for LVM?

[Paulo A G Fessel]

One big issue I see with LVM is that the configuration of VG's is half stored on hosts, half on disks. This makes reconstruction of the VG structure harder in the case of a total system failure - remember, make_tape_recovery and make_net_recovery only backup the information of vg00 by default.

VxVM, OTOH, store all information about its DG's in the disks. And with the full product, you also get snapshots of volumes, which is a great backup tool. VxVM also allows to make evacuation of physical volumes even in shared mode, something that pvmove explictly forbids when the VG is active.

I've been in touch with VxVM for 2+ years, and it really solves most of the problems HP-UX's LVM has. I don't see any problems with HP dropping LVM in the future; after all, you must pick up the right tool for the job. And even with the base product, it now has rootability and is able to mirror rootdg.

Finally, LVM without MirrorDisk/UX is not a enterprise-level software, and MirrorDisk must also be paid as VxVM full. Given the set of functionalities of VxVM, I think that it's a fair price.

Just my .02
Paulo Fessel

[Alzhy]

Good points Paulo.

I never thought of configuration storage in my various posts touting VxVM. I am practically a newbie on HPUX environments but very fast adjusting (thanks to a large part to this Forum) IMHO. LVM is I think still a solid product -- "economy solution" if you may and very simple to implement. The scare LVM folksy often get with VxVM is its perceived complexity -- which is not - really. I cannot say for sure but I started our with DiskSuite on Solaris before I had VxVM. At first it was difficult but natural learning dictates (as we do with various UNIX dialects) to find out how/what to do things on this and that environemnt...

Now on the future.. I would say HPUX will in all certainty be further developing LVM and blending it with the best features of Tru64's AdvFS and TruCluster. VxVM will still be there - hopefully being improved seamlessly integrated with HPUX, as "Insurance" ;^)

Kudos to HP for doing an excellent job in integrating VxVM with HPUX (rootability) and the Ignite framework...

[George_Dodds]

Thanks for raising the point Mark

I recently set up a 11i test box and saw the VxVM option, but thought just another option to confuse things.

Looks like i'd better take a bit more interest in it and have a play!!

Cheers

George

[F.V. Porcella]

Paulo said:

Finally, LVM without MirrorDisk/UX is not a enterprise-level software, and MirrorDisk must also be paid as VxVM full. Given the set of functionalities of VxVM, I think that it's a fair price.

Im not exactly sure what you mean by that, however, my question is, What will HP do to compensate the folks who have Enteprise OS (which includes LVM, Mirror/UX and VxFS amoung other things) when (or if)the migration to VxVM becomes NOT-optional (in 11.21 or when ever)???
Thanks
Phil

[Steven E. Protter]

My sources at HP say that LVM will be around for a long, long time. Those discussions happened 11 months ago at the last and only HP-World that I attended(2002)

I personally will not be messing with VxVM except on my education machine at hime for the following reasons:

1) Root disk capability
2) The fact that I had to rip out vxvm on HP's recommendation to get save_config from Ignite to work right on my golden image box.

Fact is new features are great but until I recieve the same capabilities I have with LVM, I will not consider a migration. My itrc time invested should not mislead anyone into thinking I don't have a huge project list workload. I do, and I'm not going to make it any bigger with an upgrade when I'm still afraid HP will pull the plug and roll out a product based on a filesystem and tools they acquired in the Compaq merger.

HP has a close and good relationship with Veritas, but is paying bucks for licensing fees.

The good long term approach is to wait and see where this goes. Then I'll sign up for a vxvm class and prepare for the migration. I'm still waiting for the unified version of HP-UX that runs on Itanium and PA-RISC.

SEP

[Alzhy]

For HP only focused admins - I can understand the FUD behind VxVM. But look at what HP has done with it? Excellent integration and very robust at that.

Anyone who's been installing HPUX 11i v1 (PARISC) since the SEP2002 release would have noticed by now that "rootability" is fully supported and works well with Ignite. Sure VxVM may have a 3 to 1 commands disadvantage but believe me - but using the GUI (VEA now its called) will bring you closer to CLI mastery in no time.

Implementing VxVM as your only VM (of course it can co-exist with LVM) will save you on MirrorDisk UX licenses as the base VxVM already allows you to mirror your root disks. Very seldom that we use MirrorDisk/UX anyway to mirror our SAN/Array disks.

We use mostly StorageWorks disks (EVA mainly) and even if the EVA is not totally supported by VxVM (SecurePath vis DMP) - I still use it to carve up my LUNS and stripe them because I have more control as to how my volumes (or lvols) are created.

And since we are also a Solaris shop, all headware and skills sets and scripts are also migrated to the HPUX environment...