I would like share one fiber disk between on two servers HP-UX 11. The
first server with read write access and the second server with only
read access.

It's possible, with or without lvm ?

Thanks

nicolas wrote:

> I would like share one fiber disk between on two servers HP-UX 11. The
> first server with read write access and the second server with only
> read access.
>
> It's possible, with or without lvm ?
>
> Thanks

With LVM you could have one system accessing the volume group
in normal read/write mode, and the other system with the volume group
activated read only.

You need to wire the disks upto both systems. Set it all up normally on
the first system, then on the second system you need to use vgimport to
let the system know about the disks, then activate the VG using
vgchange -a r vgname


Accessing the disks is the easy bit.

The difficult bit is what data are you trying to access, and how are
you going to synchronise the accesses. If you are hoping for normal
filesystem access then it is not going to work. Lots of the filesystem
stuff is happening in memory on a live system, so what you see on
disk is not going to be quite what you want. Raw disk access is no
problem.

The next major release of HP-UX on the roadmap (the one after
HP-UX 11.23)is supposed to be adding the DEC clustering technology
so you might get filesystem access at that point.

Otherwise you back to network filesystems like NFS :-(


Cheers

Ken

Agree. In addition to the fact that most of the current filesystem
info will be in memory, if you do an fsck on the second system of the
filesystem that is already mounted on the first, the results will not
be pretty.

HP_BRS


Ken Green <Ken.Green@kgcc.co.uk> wrote in message news:<3F71F51C.A4A6C0F7@kgcc.co.uk>...
> nicolas wrote:
>
> > I would like share one fiber disk between on two servers HP-UX 11. The
> > first server with read write access and the second server with only
> > read access.
> >
> > It's possible, with or without lvm ?
> >
> > Thanks
>
> With LVM you could have one system accessing the volume group
> in normal read/write mode, and the other system with the volume group
> activated read only.
>
> You need to wire the disks upto both systems. Set it all up normally on
> the first system, then on the second system you need to use vgimport to
> let the system know about the disks, then activate the VG using
> vgchange -a r vgname
>
>
> Accessing the disks is the easy bit.
>
> The difficult bit is what data are you trying to access, and how are
> you going to synchronise the accesses. If you are hoping for normal
> filesystem access then it is not going to work. Lots of the filesystem
> stuff is happening in memory on a live system, so what you see on
> disk is not going to be quite what you want. Raw disk access is no
> problem.
>
> The next major release of HP-UX on the roadmap (the one after
> HP-UX 11.23)is supposed to be adding the DEC clustering technology
> so you might get filesystem access at that point.
>
> Otherwise you back to network filesystems like NFS :-(
>
>
> Cheers
>
> Ken

HP_BRS wrote:

> Agree. In addition to the fact that most of the current filesystem
> info will be in memory, if you do an fsck on the second system of the
> filesystem that is already mounted on the first, the results will not
> be pretty.
>
> HP_BRS

You've got no sense of adventure :-)