A1000 SCSI questions

[Stuart Remphrey - Sun Computer Systems SE - QLD Australia]

Sorry, you can't treat an A1000 as a D1000. The D1000 has two internal
SCSI busses which can be either joined or brought to the outside
separately. The A1000 has a RAID controller which has only one host
SCSI bus (with IN and OUT connections). AFAIK it's only supported to use
dual connections to the same copper SCSI bus (Multi-Initiator) in cluster
configurations, in which case the OUT port would go to the second node.

+Such a configuration certainly works with D1000 arrays, as long as you
+are careful to configure Solaris to only access each drive through a
+single device-node at any one time.

You can split a D1000 bus into two, half the disks on each bus,
and use 2 SCSI busses into it. No can do with A1000.

+If you can treat the A1000s as JBOD arrays (ie: don't use the SEVM software
+to control them, just the normal Solaris SCSI drivers - in effect treat
+them as D1000s), then all will be fine. If you need volume management
+in such a configuration, then DiskSuite will do it.
+
+As for whether you can utilise the array's on-board RAID facilities
+with such a configuration, I'm not sure...there **may** be limitations
+in the SEVM software that prevent it?

You can use DiskSuite or SEVM/VxVM on top of the A1000 on-board RAID,
but this doesn't solve the single bus issue.

+Andreas Sindermann wrote:
> 
> Hello,
> 
> I'd like to mirror two complete A1000 Arrays that are connected to
> two X6541A hostadapters.
> 
> Is it possible to connect the arrays to the unused channels of the
> corresponding UNconnected hostadapter at the same time, so one
> could get this (redundant) configuration?
> (I personally don't think so, as the A1000 can only be daisychained,
> as far as I know, but I'd like to be sure)
> 
>             --------------
>   -----    | ------       |
>  |A1000|---=|X6541A|      |
>   ----- \ /| ------       |
>          X |         E450 |
>   ----- / \| ------       |
>  |A1000|---=|X6541A|      |
>   -----    | ------       |
>             --------------


---------------------------------------------------------------------
 ,-_|\  Sun Microsystems Australia  Stuart Remphrey, Systems Engineer
/     # P.O. Box 86, Albert St    stuart.remphrey@Aus.Sun.COM x.56308
\_,-\_/ Level 10, 80 Albert St   Ph (07) 3238 8308 Fax (07) 3238 8320
     v  Brisbane  QLD  4002       +61 7  3238 8308   +61 7  3238 8320
---------------------------------------------------------------------
Order a StarOffice CD in Australia: http://www.sun.com.au/staroffice/