I am wondering if there is a best practices for defining a zone on a
fibre switch where I need to
connect a p630 server to two DS4300 dasd devices. The p630 is
currently direct connected to
one of the DS4300's. I'm fairly new to switches, but believe I have
a good grasp of what I need to do, and there is actually redundancy
with two switches and two fibre controller cards in the
p630, but for simplicity sake, lets assume one of each. My question
is, is it better to have
one zone, or two defined on the switch to connect to the two
DS4300's? For example;

zone1 - fcs0 on the 630, controller slot A on DS4300 #1, controller
slot A on DS4300 #2

or

zone1 - fcs0 on the 630 and controller slot A on the DS4300 #1

zone2 - fcs0 on the 630 and controller slot A on the DS4300 #2


For performance reasons, I wish to keep both p630 fibre controllers,
fcs0 and fcs1, connected to the current DS4300 (through the switch).
I just want access to the second DS4300 (which is already connected
via switch to other servers).

A second question - on the DS4300, there are two controllers, in Slot
A and Slot B. There are
also two ports for each controller, Slot A, port 1 and 2, and Slot B,
port 1 and 2. Currently
there are only two fibre cables going to the switch, one from each
controller, port 1. Is there
any benefit to having cables also running from port 2 of each
controller? Performance wise, I didn't see any advantage to using all
4 ports (and taking up two additional ports of the switches).

Hopefully this is an appropriate place to post this question. I was
originally going to throw in some AIX questions about what all I need
to delete and rediscover, but believe I have that down.

Thanks,

Ron

zepher95@hotmail.com wrote :

> My question is, is it better to have
> one zone, or two defined on the switch to connect to the two
> DS4300's? For example;
>
> zone1 - fcs0 on the 630, controller slot A on DS4300 #1, controller
> slot A on DS4300 #2
>
> or
>
> zone1 - fcs0 on the 630 and controller slot A on the DS4300 #1
>
> zone2 - fcs0 on the 630 and controller slot A on the DS4300 #2


Ron,

In SAN, a zone is only a list of WWN (or switch ports) that are allowed
to "see" each other.

If you define a single zone, your server will "see" the two DS4300,
which is what you want, but the two DS4300 will also "see" each other,
which is not required/desirable. This is probably not an issue, as they
probably only act as FCP target, not FCP initiator, but I think it's not
"the clean way".

Two zones sounds cleaner.

By the way, this group is not SAN related, but who know a SAN related
news group ??

HTH and feel free to ask for more.

Nicolas.

zepher95@hotmail.com wrote:
> I am wondering if there is a best practices for defining a zone on a
>
> [...]
>
> For performance reasons, I wish to keep both p630 fibre controllers,
> fcs0 and fcs1, connected to the current DS4300 (through the switch).
> I just want access to the second DS4300 (which is already connected
> via switch to other servers).

See Nicolas' answer, plus depending on your FC-switch vendor/model/
software license you might want to check up on hard vs. soft zoning.
E.g. soft zoning on Brocades is done in software and only allows WWN-
based policies for device queries via SNS. That is, if a device already
"knows" about paths to its target, it can access it even if they are
not within the same zone. If security and performance are issues use
hard zoning, which in turn brings up a whole lot of other issues, be-
cause it is soley based on port/domain-ID pairs.
If you have the option - and the money ;-) - look into whatever secure
OS your switch vendor is offering. Again for Brocade there is Secure
FabricOS, which allows hard zoning with WWN-based policies.

> A second question - on the DS4300, there are two controllers, in Slot
> A and Slot B. There are
> also two ports for each controller, Slot A, port 1 and 2, and Slot B,
> port 1 and 2. Currently
> there are only two fibre cables going to the switch, one from each
> controller, port 1. Is there
> any benefit to having cables also running from port 2 of each
> controller? Performance wise, I didn't see any advantage to using all
> 4 ports (and taking up two additional ports of the switches).

I don't specifically know for the DS4300, but most storage arrays have
at least 2 ports per controller to allow a fully redundant setup. E.g.
2x HBAs per server, 2x FC-switches, 2x stroage controllers, all set up
in a mesh. Some arrays allow to define channels over one port on ctrl
A and one on ctrl B. Via internal bypass circuits you can still access
LUNs even if the ctrl you physically connected died.
Additionally you can use the ports to map different LUNs to them.

Here's a nice reference on the whole FC subject:
http://www.redbooks.ibm.com/abstract...5470.html?Open

Regards,

Frank

On Feb 7, 12:24 am, Frank Fegert <fra.nospam...@gmx.de> wrote:
> zephe...@hotmail.com wrote:
> > I am wondering if there is a best practices for defining a zone on a
>
> > [...]
>
> > For performance reasons, I wish to keep both p630 fibre controllers,
> > fcs0 and fcs1, connected to the current DS4300 (through the switch).
> > I just want access to the second DS4300 (which is already connected
> > via switch to other servers).
>
> See Nicolas' answer, plus depending on your FC-switch vendor/model/
> software license you might want to check up on hard vs. soft zoning.
> E.g. soft zoning on Brocades is done in software and only allows WWN-
> based policies for device queries via SNS. That is, if a device already
> "knows" about paths to its target, it can access it even if they are
> not within the same zone. If security and performance are issues use
> hard zoning, which in turn brings up a whole lot of other issues, be-
> cause it is soley based on port/domain-ID pairs.
> If you have the option - and the money ;-) - look into whatever secure
> OS your switch vendor is offering. Again for Brocade there is Secure
> FabricOS, which allows hard zoning with WWN-based policies.
>
> > A second question - on the DS4300, there are two controllers, in Slot
> > A and Slot B. There are
> > also two ports for each controller, Slot A, port 1 and 2, and Slot B,
> > port 1 and 2. Currently
> > there are only two fibre cables going to the switch, one from each
> > controller, port 1. Is there
> > any benefit to having cables also running from port 2 of each
> > controller? Performance wise, I didn't see any advantage to using all
> > 4 ports (and taking up two additional ports of the switches).
>
> I don't specifically know for the DS4300, but most storage arrays have
> at least 2 ports per controller to allow a fully redundant setup. E.g.
> 2x HBAs per server, 2x FC-switches, 2x stroage controllers, all set up
> in a mesh. Some arrays allow to define channels over one port on ctrl
> A and one on ctrl B. Via internal bypass circuits you can still access
> LUNs even if the ctrl you physically connected died.
> Additionally you can use the ports to map different LUNs to them.
>
> Here's a nice reference on the whole FC subject:
> http://www.redbooks.ibm.com/abstract...5470.html?Open
>
> Regards,
>
> Frank

Thanks for the replies Nicolas and Frank! You answered my questions,
and thanks for
the link to the redbook. I've been looking at others, but hadn't seen
this one. I had seen
the hard zoning, and thought it looked like a good idea, but my
switches don't support it,
low end McData, and I'm not always high on the money list. The two
zones seemed cleaner
to me as well, and had thought using the second port of the DS4300
controllers might look
a bit cleaner as well with mapping to different LUNs. Everything is
set up with redundancy
as you suggest, aside from that second port, but it would still get
through the second controller.
My switch ports will be full after doing this, but will be adding
ports late summer, and thinking
I will connect the second controller ports to the switch then.

Ron