A5000 - more details

[Dave Garrison - Systems Engineer]

> Date: Wed, 25 Mar 1998 16:51:46 -0500
> From: Seth Rothenberg <SROTHENB@montefiore.org>

> 
> How exactly is the Fibre Channel Arbitrated Loop
> hooked up?  (Is there a URL with a detailed 
> diagram?) 

There are some whitepapers at:

http://wwwwseast.usec.sun.com/storage/wp.html?view=Guest

The architecture wp should help.  (This page can also be found from www.sun.com 
and following the "Products and Solutions" link to the "Storage" link.)


> Can I take an A5000 with two Interface
> Boards, and hook up 3 hosts with two SBUS cards
> in each?
>Do I then need an additional GBIC in 
> each adapter - ie, 8 additional GBICs?
> and, to add another array to the dual rings,
> I just get another array with 2 Ibs and 4 GBICs?

Not sure I follow what you really want to do here...  Your best approach is to 
have your local Sun SE help you through the configuration details.  That's our 
job...


> 
> We are looking to use an A5000 in a High
> Availability configuration (Asymetric).
> We have a Sparc 1000, a 1000E, and a Sparc20.
> The Veritas sales rep said I can have all three
> hosts in the loop.  He did not know if I can 
> program Volume Manager to handle all 3.
> I also wonder if SDS can handle 3 hosts/diskset.

As Stuart already mentioned, you have some server h/w that doesn't support the 
A5000 array.  Also, do you really want to manage 3 hosts per storage array?   If 
you really need HA you should have more than one array for redundancy.  How 
about:

Server 1 --->  A5000 1  <- 
                          |- Server 3 
Server 2 --->  A5000 2  <-

There are several HA configuration possibilities, this is basically an N+1 
setup.  You could also have servers 1 and 2 fail over for each other.  All this 
assumes that your HA s/w supports your h/w.  Veritas HA works well, you may also 
want to check out Sun's HA/Cluster s/w (version 2.1 will support the A5000).



> 
> Also, has anyone done an upgrade to an A5000
> from SSA-112/SDS?  I am trying to sort out
> the shortage of SBUS slots in this also.  I am thinking I will run ONE
> loop during conversion, 
> and then change out the SSA Fibre card later,
> and put in the second loop then.

You could do this.  The fc-al sbus card supports 2 gbics/card.  You can actually 
connect both loops to one sbus card.  (Keep in mind that sbus max throughput is 
120MB/s while an A5000 can support 200MB/s in full duplex mode.  This is why it 
makes sense to connect each loop from a separate sbus channel (assuming you have 
one) - plus this adds some inexpensive failover redundancy.)  If you had 
multiple A5000s I recommend using the fc-al hubs to simplify connections and add 
path availability to your configuration.

With the newer Ex000 series servers you can build up a pretty nice fault 
resilient config that may meet your up-time requirements w/out the need to 
bother with HA...  :^)

- Dave



> 
> Thanks for your time.
> Seth Rothenberg
> Senior Systems Analyst
> Montefiore Medical Center
>