Is it a good practice to hook up 2 hosts to 1 D1000 so that both hosts
can see all 12 disks in it? One host would be connected to the right
array, the other host to the left array, and then a cable would connect
the 2 sides of the array together. The scsi initiator id on one host
would be changed to 6, so there are not SCSI address conflicts.

Are there any potential problems with this type of setup? Is it supported
by Sun?

Mag Newton wrote:
>
> Is it a good practice to hook up 2 hosts to 1 D1000 so that both hosts
> can see all 12 disks in it? One host would be connected to the right
> array, the other host to the left array, and then a cable would connect
> the 2 sides of the array together. The scsi initiator id on one host
> would be changed to 6, so there are not SCSI address conflicts.
>
> Are there any potential problems with this type of setup? Is it supported
> by Sun?

That is the way Sun clustering works (see, for example,
http://docs-pdf.sun.com/817-0170/817-0170.pdf), so there is no basic
problem. *BUT* you must be very careful about how the disks are
accessed, as only one system can have a file system mounted at any one
time. However, this configuration is *NOT* supported by Sun unless you
are running the Sun Cluster software.

John Howells

On Tuesday 15 July 2003 12:20 pm in comp.sys.sun.admin Mag Newton wrote:

> Is it a good practice to hook up 2 hosts to 1 D1000 so that both hosts
> can see all 12 disks in it? One host would be connected to the right
> array, the other host to the left array, and then a cable would connect
> the 2 sides of the array together. The scsi initiator id on one host
> would be changed to 6, so there are not SCSI address conflicts.
>
> Are there any potential problems with this type of setup? Is it supported
> by Sun?

This is the way that Sun Cluster connects.
BUT only one machine must mount a filesystem at any one time.
When a cluster fails over the failed machine unmounts the shared
filesystems before the standby machine mounts them.

If you want 2 machines to have access to the same filesystem at the
same time you must use NFS.

In article <pan.2003.07.15.11.20.20.196880.12292@kakazu.org >,
Mag Newton <newton@kakazu.org> wrote:

> Is it a good practice to hook up 2 hosts to 1 D1000 so that both hosts
> can see all 12 disks in it? One host would be connected to the right
> array, the other host to the left array, and then a cable would connect
> the 2 sides of the array together. The scsi initiator id on one host
> would be changed to 6, so there are not SCSI address conflicts.
>
> Are there any potential problems with this type of setup? Is it supported
> by Sun?

If you want both systems to be able to access the D1000 disks
_simultaneously_, you'll need to use something other than HFS and
install clustering software on both systems. This includes both systems
mounting the disks (one read and the other read/write).

If you want one system to be the "standby" and be able to mount the
logical volumes in the D1000, again there's clustering software that
does this.

What are you trying to accomplish?

--
DeeDee, don't press that button! DeeDee! NO! Dee...

Thanks for everyone's replies.

The goal of this setup is to have a way to recover from a failed system or
its disks. They want to have a pseudo cluster. If any componenent fails,
any switching of CPU's or disks will have to be done manually.

I forgot to mention that Veritas is being used to manage the
disks in the D1000.


On Tue, 15 Jul 2003 06:20:20 -0500, Mag Newton wrote:

> Is it a good practice to hook up 2 hosts to 1 D1000 so that both hosts
> can see all 12 disks in it? One host would be connected to the right
> array, the other host to the left array, and then a cable would connect
> the 2 sides of the array together. The scsi initiator id on one host
> would be changed to 6, so there are not SCSI address conflicts.
>
> Are there any potential problems with this type of setup? Is it
> supported by Sun?