SAN and Windows 2003 Servers

[Ludvig]

Hi!

We have a SAN with an EVA3000 and two san switches. We have two new servers running 2003 enterprise edition with a single fiber card in each. We have zoned the cards on port level but when we present disks we get dubble on every disk and half of the disks are non workable. What are we doing right. Every card has a one optical cable with two cables in it. What are we doing wrong?

[Uwe Zessin]

If by 'dubble' you mean that you see twice the number of disks, then you might not have properly zoned the fibre channel adapters.

An EVA has two controllers, each with two host ports. Both host ports of a single controller are connected to different switches. When you create a virtual disk and present it to a 'host' it is visible on all four controller ports.

However: only one controller is really managing the virtual disk - the other is just presenting it so that the any multipath software on the host knows that there are redundant path available.

So, your servers 'see' two path to the same disk. The problem is that a pure Windows system does not know how to deal with redundant path. In this case you have two choices:

1) assign the virtual disk to one controller using 'failover/failback' and create a zone containing the host's fibre channel adapter and the active EVA controller in this fabric.

2) buy and install the Secure Path software. It filters out any redundant path and can switch over if, for example, one controller has failed. Here is informaion about secure path:
http://h18000.www1.hp.com/products/sanworks/secure-path/index.html

Each optical cable has two 'fibers', because one fibre is carrying the light from the switch to the server's adapter and the other is carrying the light from the adapter to the switch. If you check, you will see that each of EVA's four host ports have two connections (transmit + receive) as well.

[Ludvig]

Hi!

I am kinda a novice to all this but thanks for the reply. I am kinda curious about step one that you wrote me about, the failback thing but I am not sure if I understand it. I will give you a better explaination of our setup. Was really tired yesterday. This is how it looks.

We have a eva3000 with 2 san switches (don't know exact model).

The server I am trying to configure is a Proliant DL360. It contains only one fiberchannel card that is only connected to one of the san switches with one optic cable that has two bundled cables

I went in to that san switch, gave it an alisas set the port to 1,3 which it is conencted to, put it into our 2000 zone as my hp technican said. He said that should be enough as long as I don't have another fibercard in it connected to the other switch because the I need secure path.

The 2000 Zone that we have only contains servers that have two fiberchannel cards and that are running secure path. We don't wanna run that on this server because it's just a testserver.

The result now is that I get twice the amount of virtual disks presented to that server.

What exactly should I do. Could you please explain in more detail. I really feel like I want to step on my HP technicans toes because he has been kinda arogant about our problem and I want to bring this up as a issue with the HP support.

[Uwe Zessin]

The failback setting makes sure that the virtual disk goes back to the controller it was originally assigned to once the problem is fixed.

I have already explained why there are two fibers in the optical cable - please re-read my first response.

Your '2000 zone' very likely contains two EVA controller ports (one from each controller). The reason your DL360 sees each virtual disk two times is that there are two paths. If you like to keep it that way, then you need a copy of Secure Path for the DL360, too.


You should get somebody who is familiar with switch zoning and EVA management and show him my responses.

[Ludvig]

Hi!

Thanks for all the help Uwe. I checked our w2k zone and it was like you said. It had both controllers in it. I did a new zone and only added one of the controllers. Shouldn't matter which one right?

I also did a new virtual disk and set failover on it. When you choose it you can take path a or path b does it matter which one it is?

I made an alias for the server and added the port for it. The port is still 1,3 on the first switch. I then added the alias into the new zone and presented my new virtual disk for the server.

Problem now is that I don't see any virtual disks at all. Did I do something wrong in my thinking. I think everything looks right according to your descrition.

I will be really happy if you will respond as soon as possible. HP tecs are impossible to get hold on during the vacation season. :(

regards
Ludvig

[Ludvig]

Update:

The zone that I did is not working. I took the old w2k zone and just removed one of the eva controller and then it works fine. Did I do something wrong with my zone? Do I have to check the world wide names in the zone config under edit. Something small is missing I am just frustrated about this small detail. :)