From: <>
Date: Sat Jul 27 2002 - 10:49:18 EDT
Please find the replies which helped me out. Many thanx for sugesstions and



Subject: Re: Hitachi (HDS) SAN
Date: Fri, 12 Jul 2002 08:11:04 -0700
From: John Martinez <>

> 1) These WWNs and Port numbers - How do they get created? Is it by HDS,
Fabric, Brocade or the JNIfcaw driver?

By the devices on the fabric. the LUN IDs get created by the storage unit.

> 2) What information is used in creating these? If I know what goes behind I
might be able to get unique WWNs/Port numbers created and in tun I would be
able to use them for persistent binding all across our servers.

Probably the LUN number in the case of the storage. You don't get much
choice, usually, when it comes to HBAs.

> 3) Can I have some pointers for good documentation/pdf files related to this
SAN setup? I cant find much admin type guides on HDS/Brocade web sites apart
from glossy prsentations.

Get the Brocade book on SANs. There were a few good articles over at
Sysadmin Magazone online dated from early last year. I haven't found
much good information online yet.

> 4) Is there any freeware/hds/JNI utility which can be used to generate the
WWN/Port numbers apart from looking into messages file. I am trying to
document these for DR purposes. I am after something like luxadm.

Not that I know of.

The problem that you are seeing where production disks are showing up is
called selective LUN presentation, or LUN masking as some vendors call it.

Even though you've zoned the HDS arrays and the servers, all of the LUNs
will show up to all of the servers that are in the zone because they are
in the same zone.

Arrays usually have the capability to take individual LUNs (I'm not too
familiar with HDS arrays, but the ones we use do have the capability)
and "present" them to specific WWNs. In this case, those specific WWNs
would be the HBAs in a particular server.

Good luck,


Subject: RE: Hitachi (HDS) SAN
Date: Fri, 12 Jul 2002 10:12:14 -0600
From: "Robert Legate" <>
To: "''" <>

Sounds like you need to do some LUN masking so that only the machines you
want can see the proper LUNs you want. It can easily be done using EZfibre.


Subject: RE: Sunmanagers: Hitachi (HDS) SAN
Date: Fri, 12 Jul 2002 16:03:54 +0100

Welcome to the wonderful world of HDS SAN's. ;-)

You CAN 'zone' using the fcaw.conf but I would recommend zoning preferably
from the Brocade Fabric. This is much safer and stops you accidentally
attaching the wrong disk (VERY easily done, and very disastrous. I know from
experience :-( It sounds like this hasn't be done for your system

1) Port numbers and WWN's for the HDS are generated internally by the HDS. A
bit like a NIC MAC address. Specfic to the particular array.

2) WWN's are like MAC address's and generated down to manufacturer, model,
serial and some random stuff.
Port numbers very similar. However for the last 2 digits of the port wwn tell
you which port it is on that particular array ie 00 = 1A
11 = 1B
01 = 2A
10 = 2B

excerpt from sd.conf
name="sd" class="scsi" target=1 lun=0 hba="fcaw0" wwn="5000XXXXXXXXXX10";
name="sd" class="scsi" target=1 lun=1 hba="fcaw0";
name="sd" class="scsi" target=1 lun=2 hba="fcaw0";
name="sd" class="scsi" target=1 lun=3 hba="fcaw0";
name="sd" class="scsi" target=2 lun=0 hba="fcaw2" wwn="5000XXXXXXXXXX01";
name="sd" class="scsi" target=2 lun=1 hba="fcaw2";
name="sd" class="scsi" target=2 lun=2 hba="fcaw2";
name="sd" class="scsi" target=2 lun=3 hba="fcaw2";


Mark Dorman - ITSDTSU&UN - Halifax PLc - HBOS
Watashi no kuruma o namae wa Kaori desu.

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