Mount LVM volumes under Linux

[Robert Early_3]

We're investigating the possibility of backing up HPUX machines via a Linux box, but the current LAN is sluggish. However we do have the HP machines on a SAN and I was wondering if we were to attach the Linux machine to the SAN, could it mount the HPUX volumes and read the files in them? Or is HPUX's LVM completely alien to it?

[Stefan Farrelly]

I would say no chance. You could probably connect them to a SAN and put them in the same zone but no way of mounting an HP volume while it is inuse (on the HP server) on a linux server. Even if it wasnt in use there isnt the facility to import an HP volume onto Linux. Even the LVM bit could possibly be overcome as LVM is available for LVM (not sure how compatible though). Youre going to have to put up with a network backup or try nfs mounting HP to Linux - this will work. Easiest thing to do is upgrade the network cards to 100/Gigabit.

[Robert Early_3]

Well, it wouldn't be a volume that's in use (using Business Copy), it was more the compatibility of the filesystem I was wondering about.Oh well, looks like we'll have to stick to the network backup. We found rsync and gigabit ethernet was the best we could do otherwise.

[Todd McDaniel_1]

Even if the LVM tools were available under Linux, which I don't know if they are, the data structures of the disks and the LIF structure of HPUX disks and the extend based structure would prevent them from being compatible on a Linux file structure.

So I seriously doubt that you would be able to mount them on a Linux box. I fear the only way is to at least tar the data then cp it. That might save you some time.

[Robert Binkhorst]

Hi,

LVM under Linux uses the same commands that HP-UX LVM uses. However, I agree with Tod that the structures on disk are probably the same, although I don't know.

More documentation can be found here:
http://www.sistina.com/products_lvm.htm

They also have a mailing list, you could try posting that question here.

[Virgil Chereches_2]

What you need is VxVM - Veritas Volume Manager - a basic version is available on HP-UX11i.
You may upgrade your LVM volumes to VxVM volumes and buy a license for Veritas Volume Manager for Linux.
Anyway, you must be sure that the compatibility is 100 percent achieved. You may take a look at www.veritas.com.


Best regards,
Virgil

[Todd McDaniel_1]

If you have LVM data structures on HPUX and want to go to Veritas VXVM you will need to backup data and destroy/recreate all your VGs...

AFAIK, you can't "upgrade" LVM vxfs to VXVM. You must creat new VGs with Veritas tools, however, they are similar but not entirely compatibile.

[Virgil Chereches_2]

Todd, I'm sorry to speak against you but it's possible to convert from LVM to VxVM.
If you take a look at "Veritas Volume Manager Migration Guide" (from http://ftp.support.veritas.com/pub/support/products/VolumeManager_UNIX/hp_vm30_migration_236915.pdf)
you can see that:
//The vxvmconvert process converts LVM volume groups to VxVM disk groups in place. In reality, the utility changes disks within LVM volume groups to VxVM disks by taking over the areas of the disks used for LVM configuration information, and creating the equivalent VxVM volume configuration information. User data, the portions of the disks used for file systems, databases, etc., are not affected by the conversion.//


Best regards,
Virgil

[dirk dierickx]

Upgrading from HPUX lvm to Veritas VM seems locigal, as didn't HP license the veritas VM for creating LVM? i though so.

[Emory Cowan_1]

We're doing something similar

The possibility of backing up HPUX machines via a Linux box, is feasable using the UFS (read only mode)driver and mounting the HPUX Volume.

We are doing a similar technique to migrate Solaris(UFS)to Linux.

HPUX LVM partition type? hfs VxFS
You might have to copy your '/' to a "whole disk" under HPUX and then try to access that from Linux.

[Hein van den Heuvel]

I would push a (compressed!) tar file over a gigabit network myself.
However, before doing so, I'd be mighty tempted to create a test tar file on a RAW volume as presented to one OS. Unpresent the volume, Present to the next OS and see if 'untar' works for the test case. If that works...

Cheers,
Hein.