[linux-lvm] dual adapter machine

[linux-lvm] dual adapter machine

[Michael Lausch]

We are going to use linux LVM on some servers using 2 FCAL adapters
per machine, since our RAID System (HP XP256) has two FCAL
channels. So in order to have no single point of failure, we want to
use 2 FCAL adapters in each machine, connected to the same (virttual)
disks. This means i see the same partition on two controlers.

For example: controller 1, SCSIID 3, LUN 1, Partition 1
and          controller 2, SCSIID 3, LUN 1, Partition 1

refer to the same blocks.

So when everything is okay i'll talk to the disk through c1d3l1s1 (in
solaris notation). When this FCAL has an error, i want to talk to the
same disk via c2d3l1s1. How can this be done with linux LVM?

Anybody got any ideas? 

thanks in advance.
-- 
michael lausch

Re: [linux-lvm] dual adapter machine

[Eric Smith]

I think LVM should be made to do it.  Veritas calls theirs  DMP: Dynamic Multi
Pathing.  What's cool is, not only do you eliminate your single point of
failure. but also DMP round-robins requests between the two paths when both are
active, increasing your throughput.

LVM should do this, imho!


Franken Klaus wrote:

> Hi,
>
> there is a commercial software called "Duplex Data Manager (DDM)" from
> Fujitsu-Siemens-Computers for exactly this.
> Unfortunately I can't found an online documentation.
> I can send you a PDF and a powerpoint ducumentation if needed.
> In the german magazin "Linux Enterprise" (1.2000) was an article about DDM.
>
> DDM seems very well designed, you can use it in conjunction with MD, LVM etc.
>
> But an open-source tool would be nice too.
>
> Klaus.Franken@fth2.siemens.de    +49 911 978 3707
> Siemens Business Services IP 21F
>
> > -----Original Message-----
> > From: Michael Lausch [mailto:mla@1012surf.net]
> > Sent: Monday, August 07, 2000 12:33 PM
> > To: linux-lvm@msede.com
> > Subject: [linux-lvm] dual adapter machine
> >
> >
> >
> > We are going to use linux LVM on some servers using 2 FCAL adapters
> > per machine, since our RAID System (HP XP256) has two FCAL
> > channels. So in order to have no single point of failure, we want to
> > use 2 FCAL adapters in each machine, connected to the same (virttual)
> > disks. This means i see the same partition on two controlers.
> >
> > For example: controller 1, SCSIID 3, LUN 1, Partition 1
> > and          controller 2, SCSIID 3, LUN 1, Partition 1
> >
> > refer to the same blocks.
> >
> > So when everything is okay i'll talk to the disk through c1d3l1s1 (in
> > solaris notation). When this FCAL has an error, i want to talk to the
> > same disk via c2d3l1s1. How can this be done with linux LVM?
> >
> > Anybody got any ideas?
> >
> > thanks in advance.
> > --
> > michael lausch
> >

RE: [linux-lvm] dual adapter machine

[Franken Klaus]

Hi,

there is a commercial software called "Duplex Data Manager (DDM)" from
Fujitsu-Siemens-Computers for exactly this.
Unfortunately I can't found an online documentation.
I can send you a PDF and a powerpoint ducumentation if needed.
In the german magazin "Linux Enterprise" (1.2000) was an article about DDM.

DDM seems very well designed, you can use it in conjunction with MD, LVM etc.

But an open-source tool would be nice too.


Klaus.Franken@fth2.siemens.de    +49 911 978 3707
Siemens Business Services IP 21F


> -----Original Message-----
> From: Michael Lausch [mailto:mla@1012surf.net]
> Sent: Monday, August 07, 2000 12:33 PM
> To: linux-lvm@msede.com
> Subject: [linux-lvm] dual adapter machine
> 
> 
> 
> We are going to use linux LVM on some servers using 2 FCAL adapters
> per machine, since our RAID System (HP XP256) has two FCAL
> channels. So in order to have no single point of failure, we want to
> use 2 FCAL adapters in each machine, connected to the same (virttual)
> disks. This means i see the same partition on two controlers.
> 
> For example: controller 1, SCSIID 3, LUN 1, Partition 1
> and          controller 2, SCSIID 3, LUN 1, Partition 1
> 
> refer to the same blocks.
> 
> So when everything is okay i'll talk to the disk through c1d3l1s1 (in
> solaris notation). When this FCAL has an error, i want to talk to the
> same disk via c2d3l1s1. How can this be done with linux LVM?
> 
> Anybody got any ideas? 
> 
> thanks in advance.
> -- 
> michael lausch
>