Hi,

I have the opportunity to do some "on the job learning" during the next
week or so with some SAN equipment, and I was hoping that you all here
could help me get through some of the initial rough spots.

The SAN is an almost fully loaded EMC (CX700, I think).  From what I've
been told, it has two "service processors" (SP), with 4 fibre channel
ports each, and a bunch of drives.  I also have use of an EMC FC switch
(a DSM-32, I think).

Ok.

I've been able to muddle through most of the initial configuration of
the SAN itself, and the FC switch.

To keep things simple, I installed an Emulex LP8000 (2 ports) HBA into a
Windows 2000 PC, just for starters, and I've been able to get the SAN to
"see" the PC's HBA ports (in the switches web configurator) and, I think
vice-versa.

Again, just for starters, and to keep thing simple, I made the following
physical connections so far:

HBA port1 ---> FC Switch port 27
HBA port2 ---> FC Switch port 28

SAN SPA port 0 --> FC Switch port 30
SAN SPB port 0 --> FC Switch port 31

And now, I'm trying to figure out what I should be doing for the next
steps, so I have some questions:

1) A kind of basic question, but with a SAN like the EMC CX series, can
I "get to" or access all of the drives in the SAN from any/all of the
ports on the SPs?  In other words, are all of the ports of each of the
SAN's SPs essentially the same?

2) I have the impression that I needed to "create some zones", and so in
the FC switch configurator, I did that (or tried).  I initially created
one zone, and put the WWNs for HBA port1, HBA port2, SAN SPA port 0, and
SAN SPB port 0 into a single zone that I named "Win2K".

Like I said, I'm still kind of struggling through all of this, but is
the above a good way to do the zoning (both HBA ports and each of the
SPA/B ports in one single zone)?

- I guess I don't quite understand the purpose or reason for the zones,
but I have the impression from things that I've read that having all of
those 4 ports in one zone will allow them all to "talk" to each other?

- Or, should I put, say, HBA port1 and SAN SPA port 0 in one zone, and
HBA port 2 and SAN SPB port 0 in a separate zone?

- Of the two approaches above, why would I do one vs. the other?
- Actually, I'm wondering if, with the former zone config (all ports in
one zone), when I get further along and start trying to make the storage
on the SAN visible to the PC, I might end up with the PC "seeing" the
same storage twice?


I know that these are probably really elementary questions, but I'm also
hoping that this can be a good opportunity to learn something.
Unfortunately, I don't have anyone (yet) who's readily available to help
me along .

Thanks in advance,
Jim

[ Post a follow-up to this message ]

On Mon, 13 Sep 2004 21:18:58 -0400, ohaya wrote:

> Hi,
>
> I have the opportunity to do some "on the job learning" during the next
> week or so with some SAN equipment, and I was hoping that you all here
> could help me get through some of the initial rough spots.
>
> The SAN is an almost fully loaded EMC (CX700, I think).  From what I've
> been told, it has two "service processors" (SP), with 4 fibre channel
> ports each, and a bunch of drives.  I also have use of an EMC FC switch
> (a DSM-32, I think).
>
> Ok.
>
> I've been able to muddle through most of the initial configuration of
> the SAN itself, and the FC switch.
>
> To keep things simple, I installed an Emulex LP8000 (2 ports) HBA into a
> Windows 2000 PC, just for starters, and I've been able to get the SAN to
> "see" the PC's HBA ports (in the switches web configurator) and, I think
> vice-versa.
>
> Again, just for starters, and to keep thing simple, I made the following
> physical connections so far:
>
> HBA port1 ---> FC Switch port 27
> HBA port2 ---> FC Switch port 28
>
> SAN SPA port 0 --> FC Switch port 30
> SAN SPB port 0 --> FC Switch port 31
>
> And now, I'm trying to figure out what I should be doing for the next
> steps, so I have some questions:
>
> 1) A kind of basic question, but with a SAN like the EMC CX series, can
> I "get to" or access all of the drives in the SAN from any/all of the
> ports on the SPs?  In other words, are all of the ports of each of the
> SAN's SPs essentially the same?
Each SP can have control of any drive in the CX700 only.  SP A usually has
a half and SPB has the other half.  Your mailage may very.  SPA abd B will
"tresspass" over drives in case of failure of either SP.

SP's can see some other specail drive in other array but that is not a
standard config.
>
> 2) I have the impression that I needed to "create some zones", and so in
> the FC switch configurator, I did that (or tried).  I initially created
> one zone, and put the WWNs for HBA port1, HBA port2, SAN SPA port 0, and
> SAN SPB port 0 into a single zone that I named "Win2K".
zone WWNN of SPA to WWNN HBA1
zone WWNN of SPB to WWNN HBA2
haveing 2 pouts on one HBA is still a single point of failure.
>
> Like I said, I'm still kind of struggling through all of this, but is
> the above a good way to do the zoning (both HBA ports and each of the
> SPA/B ports in one single zone)?
>
> - I guess I don't quite understand the purpose or reason for the zones,
> but I have the impression from things that I've read that having all of
> those 4 ports in one zone will allow them all to "talk" to each other?
>
roughly the same reson host have /etc/host

> - Or, should I put, say, HBA port1 and SAN SPA port 0 in one zone, and
> HBA port 2 and SAN SPB port 0 in a separate zone?
>
> - Of the two approaches above, why would I do one vs. the other?
> - Actually, I'm wondering if, with the former zone config (all ports in
> one zone), when I get further along and start trying to make the storage
> on the SAN visible to the PC, I might end up with the PC "seeing" the
> same storage twice?
Maybe depending on other issues  EMC power path and Access Logix
>
> I know that these are probably really elementary questions, but I'm also
> hoping that this can be a good opportunity to learn something.
> Unfortunately, I don't have anyone (yet) who's readily available to help
> me along .
>
> Thanks in advance,
> Jim

NP Guy

[ Post a follow-up to this message ]

"ohaya" <ohaya@cox.net> wrote in message news:41464702.BD254E40@cox.net...
> Hi,
>
>snip

> Again, just for starters, and to keep thing simple, I made the following
> physical connections so far:
>
> HBA port1 ---> FC Switch port 27
> HBA port2 ---> FC Switch port 28
>
> SAN SPA port 0 --> FC Switch port 30
> SAN SPB port 0 --> FC Switch port 31
>
> And now, I'm trying to figure out what I should be doing for the next
> steps, so I have some questions:
>
> 1) A kind of basic question, but with a SAN like the EMC CX series, can
> I "get to" or access all of the drives in the SAN from any/all of the
> ports on the SPs?  In other words, are all of the ports of each of the
> SAN's SPs essentially the same?

yes all those ports are the same. Each should give access to all drives, but
please see below

>
> 2) I have the impression that I needed to "create some zones", and so in
> the FC switch configurator, I did that (or tried).
> snip>
> - I guess I don't quite understand the purpose or reason for the zones,

You should use zones to prevent multiple host from landing on,  and possibly
destroying the content of, the same LUN/volume.

A general comment if I may: practising is good, but if you lack the basic
theory your efforts could be fruitless. Remember the million monkeys banging
on keyboards?

I say: "Get the concepts straight first "

Also,  you should have plenty of software loaded on those SP: start
NaviSphere and it should open the array for you

Have fun

[ Post a follow-up to this message ]

ohaya wrote:
...
> HBA port1 ---> FC Switch port 27
> HBA port2 ---> FC Switch port 28
>
> SAN SPA port 0 --> FC Switch port 30
> SAN SPB port 0 --> FC Switch port 31
...
> - I guess I don't quite understand the purpose or reason for the zones,
> but I have the impression from things that I've read that having all of
> those 4 ports in one zone will allow them all to "talk" to each other?
>
> - Or, should I put, say, HBA port1 and SAN SPA port 0 in one zone, and
> HBA port 2 and SAN SPB port 0 in a separate zone?
>
> - Of the two approaches above, why would I do one vs. the other?

If you just want to make the host see the storage, both methodes of zoning w
ill
work. With separate zones however, pulling a cable or disabling a port in zo
ne1
will have no effect on traffic in zone2, so that is a clear advantage if you
care about failover (I assume you do since you have everyting dual-ported).

You can think of zones as collections of ports that can see each other and a
re
notified of each other's status. So if you really want a highly redundant
configuration, you would create two separate zones (on two separate frontend
switches in order to survice switch failure).

> - Actually, I'm wondering if, with the former zone config (all ports in
> one zone), when I get further along and start trying to make the storage
> on the SAN visible to the PC, I might end up with the PC "seeing" the
> same storage twice?

The HBA driver should be able to recognize that it can see the same device
through two ports, and present only a single device to you.
Actually with the one big zone, there will be 4 paths from the HBA to the vo
lume :

HBA port 1 to SAN SPA port 0
HBA port 1 to SAN SPB port 0
HBA port 2 to SAN SPA port 0
HBA port 2 to SAN SPB port 0

Your HBA driver should be able to handle this. I don't know if the driver fo
r
your particular HBA and platform allows you to do active/active I/O (ie. use
 all
paths to a volume simultaneously to send SCSI requests), or just picks one a
nd
uses the other ones in case of failover.

Arne Joris

[ Post a follow-up to this message ]

> You should use zones to prevent multiple host from landing on,  and possib
ly
> destroying the content of, the same LUN/volume.


With the above, you've touched upon the thing that is puzzling me about
zones/zoning.  I've often seen the example (in reading) of using zones
to prevent a Windows server from seeing say, a Solaris LUN, and
vice-versa, to keep the servers from damaging the storage of each other.

But, I have the impression that both SPs can "get to" all of the drives
in the SAN.  Now, let's say instead of having only one PC with a dual
HBA, I had a Windows server with a single-channel HBA, and a separate
Solaris server also with a single-channel HBA.

Now, even if I create zones such that Windows HBA port can only see SPA
port 0 and Solaris port can only see SPB port 0, and since both SPA and
SPB can see all drives in the SAN, how do the zones stop the Windows
server from seeing the LUNs for the Solaris server and vice-versa?

I guess what I'm saying is that because zones/zoning only control the
path from the server port to the SP port, and since each SP can see all
drives in the SAN, it seems like JUST ZONING BY ITSELF doesn't seem to
be able to accomplish the protection (Windows can't see Solaris LUNs,
Solaris can't see Windows LUNs)?




> A general comment if I may: practising is good, but if you lack the basic
> theory your efforts could be fruitless. Remember the million monkeys bangi
ng
> on keyboards?
>
> I say: "Get the concepts straight first "

I kind of knew that I would be having the chance to do what I'm doing,
awhile ago (weeks ago), and have been reading and reading a lot of books
etc. in preparation, but reading it in books and actually doing it is a
little different.  So, I appreciate all of your patience with my
questions...

Jim

[ Post a follow-up to this message ]

>
> The HBA driver should be able to recognize that it can see the same device
> through two ports, and present only a single device to you.
> Actually with the one big zone, there will be 4 paths from the HBA to the 
volume :
>
> HBA port 1 to SAN SPA port 0
> HBA port 1 to SAN SPB port 0
> HBA port 2 to SAN SPA port 0
> HBA port 2 to SAN SPB port 0
>
> Your HBA driver should be able to handle this. I don't know if the driver 
for
> your particular HBA and platform allows you to do active/active I/O (ie. u
se all
> paths to a volume simultaneously to send SCSI requests), or just picks one
 and
> uses the other ones in case of failover.


Arne,

Thanks for your clear explanations!!

Some initial testing that I was doing, with a situation akin to what you
described above is kind of what triggered my original post.

I had put both PC/HBA ports and the one port from each of the CX700 SPs
into a single zone, and I had created two LUNs.

When I went to the Windows PC, instead of just seeing two new "drives",
I saw four.  Also, although Windows seemed to see four drives, two of
the four drives acted a little strange.  For example, when I tried to do
check disk, I'd get an error saying that the drive was corrupted or
something like that.

I was kind of guessing that for some reason, Windows was getting
confused, and was seeing the two drives twice (once via each HBA
channel).

I got another fellow at work to step me through some stuff, and we
deleted the zone and rebuilt it the same way again, and guess what?
After we had done all that, this time Windows only saw 2 new drives.

I really don't know why the above happened.  I've gone over and over
what I did the first time, but it was the same as when I did it the
second time.

Puzzling...

Jim

[ Post a follow-up to this message ]

On Tue, 14 Sep 2004 15:52:40 -0400, ohaya <ohaya@cox.net> wrote:

> 
>
>
>With the above, you've touched upon the thing that is puzzling me about
>zones/zoning.  ...
>I guess what I'm saying is that because zones/zoning only control the
>path from the server port to the SP port, and since each SP can see all
>drives in the SAN, it seems like JUST ZONING BY ITSELF doesn't seem to
>be able to accomplish the protection (Windows can't see Solaris LUNs,
>Solaris can't see Windows LUNs)?
>

This is correct.  I can't speak for EMC storage, but on HP storage there is
Selective Presentation in addition to port zoning.  This means that the
storage controller only presents the LUN to the server(s)' HBAs with
specific WWN or connection names.  SAN's couldn't exist without this, so it
would surprise me if EMC didn't provide this capability as well.

--- jls
The preceding message was personal opinion only.
I do not speak in any authorized capacity for anyone,
and certainly not my employer.
(get rid of the xxxz in my address to e-mail)

[ Post a follow-up to this message ]

On Tue, 14 Sep 2004 15:52:40 -0400, ohaya wrote:

> 
>
>
> With the above, you've touched upon the thing that is puzzling me about
> zones/zoning.  I've often seen the example (in reading) of using zones
> to prevent a Windows server from seeing say, a Solaris LUN, and
> vice-versa, to keep the servers from damaging the storage of each other.
>
> But, I have the impression that both SPs can "get to" all of the drives
> in the SAN.  Now, let's say instead of having only one PC with a dual
> HBA, I had a Windows server with a single-channel HBA, and a separate
> Solaris server also with a single-channel HBA.
>
> Now, even if I create zones such that Windows HBA port can only see SPA
> port 0 and Solaris port can only see SPB port 0, and since both SPA and
> SPB can see all drives in the SAN, how do the zones stop the Windows
> server from seeing the LUNs for the Solaris server and vice-versa?
>
> I guess what I'm saying is that because zones/zoning only control the
> path from the server port to the SP port, and since each SP can see all
> drives in the SAN, it seems like JUST ZONING BY ITSELF doesn't seem to
> be able to accomplish the protection (Windows can't see Solaris LUNs,
> Solaris can't see Windows LUNs)?
>
>
>
> 
>
> I kind of knew that I would be having the chance to do what I'm doing,
> awhile ago (weeks ago), and have been reading and reading a lot of books
> etc. in preparation, but reading it in books and actually doing it is a
> little different.  So, I appreciate all of your patience with my
> questions...
>
> Jim

Zoneing is a method of mapping the host to the array.
In order to prevent 2 host from seeing the same device in your caes a LUN
in the CX you use Access Logix the is know as LUN masking.


Guy

[ Post a follow-up to this message ]

"ohaya" <ohaya@cox.net> wrote in message news:41474C08.B0885C7E@cox.net...
> 
>
>
> With the above, you've touched upon the thing that is puzzling me about
> zones/zoning.  I've often seen the example (in reading) of using zones
> to prevent a Windows server from seeing say, a Solaris LUN, and
> vice-versa, to keep the servers from damaging the storage of each other.
>
> But, I have the impression that both SPs can "get to" all of the drives
> in the SAN.  Now, let's say instead of having only one PC with a dual
> HBA, I had a Windows server with a single-channel HBA, and a separate
> Solaris server also with a single-channel HBA.
>
> Now, even if I create zones such that Windows HBA port can only see SPA
> port 0 and Solaris port can only see SPB port 0, and since both SPA and
> SPB can see all drives in the SAN, how do the zones stop the Windows
> server from seeing the LUNs for the Solaris server and vice-versa?
>
> I guess what I'm saying is that because zones/zoning only control the
> path from the server port to the SP port, and since each SP can see all
> drives in the SAN, it seems like JUST ZONING BY ITSELF doesn't seem to
> be able to accomplish the protection (Windows can't see Solaris LUNs,
> Solaris can't see Windows LUNs)?
>
You're right, my answer was inaccurate. This paper
http://www.qlogic.com/documents/dat...
unmasking.pdf

should do a  better job  than I did explaining that .

[ Post a follow-up to this message ]

jlsue, st0ut, ahedge, and everyone else who's replied to this thread:

Thanks for the responses, I really appreciated it, and your comments
have greatly helped me understand.


jlsue,

It looks like on the CX700, in their Navisphere tool, you create
"Storage Groups", and then you move "hosts" and "LUNs" into the Storage
Groups, and this seems to determine which LUNs can be seen by which
hosts.


So, I'm still kind of wondering about what I asked in my original post.
I've seen that statement or something similar, about using zones to
prevent access, in several places, including books.  At least with the
CX700, it looks like the only thing that controls this is the Storage
Groups, and it looks like the Storage Groups don't have anything to do
with zones (which I guess are a "switch thing", not a CX700 thing).

Jim




ahedge wrote:
>
> "ohaya" <ohaya@cox.net> wrote in message news:41474C08.B0885C7E@cox.net...
 
> You're right, my answer was inaccurate. This paper
> http://www.qlogic.com/documents/dat....lunmasking.pdf
>
> should do a  better job  than I did explaining that .

[ Post a follow-up to this message ]