topic Re: Win2003 host and San Sufer problem in HPE EVA Storage

Win2003 host and San Sufer problem

Mikhail_4 — Fri, 26 Mar 2004 07:05:24 GMT

Hello,
we have a problem with a host connecting to VA7410 in SAN with StorageWorks SAN Switch 2/16 EL:
when using SAN Surfer to configure paths to LUNS (preferred and alternate),
only one path is seen, although we have 2 controllers on VA, and the LUN is located on 2-nd RG, but host sees that LUN through the 1-st (alternate) RG. Through the port of 2-nd RG host can see only LUN 0.
Trying to reconfigure it manually or automatically doesn't help - the host just doesn't see them at all.
Does anyone know anthing about this ?

Re: Win2003 host and San Sufer problem

Uwe Zessin — Fri, 26 Mar 2004 07:29:32 GMT

Mikhail,
a RG (redundancy group) is an object that maintains a group of disks. A VA7410 has two RGs (RG1 and RG2). Each one is maintained by one of the controllers. A LUN is then created to take storage space from one RG and present it though the host ports. I don't have much experience with the VA7000 series, but it is my understanding that a LUN is visible through both controllers. However, if you try to access a LUN that is located in RG1 through controller 2, he will re-route the I/O request over an internal bus to controller 1 which will process the request.

I don't have experience with SAN surfer, but using other software I was able to look into the Windows registry and check each SCSI port if it was able to see the LUNs. The multipath driver was layered on top of this.

Re: Win2003 host and San Sufer problem

Mikhail_4 — Fri, 26 Mar 2004 07:51:06 GMT

I know the basics, and what I meant was that the host should see the LUN on 1-st RG through the port of 1-st controller (responsible for working with RG-1), and it doesn't.
Although we have the right picture on the other host (Win2003), it can see the LUN two ways: preferred and alternate. Here (on the problem host) it only sees the alternate path.

Re: Win2003 host and San Sufer problem

Uwe Zessin — Fri, 26 Mar 2004 08:57:35 GMT

I see. Do I understand you correctly that the affected server can see LUN 0 through both adapters, but the remaining LUN(s) only through one adapter? If that is true it sounds like you use Secure Manager - are you sure your LUN masking is correct?

Re: Win2003 host and San Sufer problem

Mikhail_4 — Mon, 29 Mar 2004 05:22:47 GMT

You're right about the problem and Secure Manager.
But I'm not sure I know what LUN masking is ... Could you describe it more comprehensive, pls

Re: Win2003 host and San Sufer problem

Uwe Zessin — Mon, 29 Mar 2004 05:52:01 GMT

LUN masking ensures that servers can only access LUNs that they need access to.

Image two Windows servers that are not clustered. By default the storage array presents all LUNs to both servers. Both servers boot and will automatically mount all disks with a file system on them they recognize. Access to the data is unsynchronized and that results in data corruption.

Back to you problem, it sounds like the table that defines which fibre channel adapter has access to which LUN is too strict.

Use the 'armsecure' command to retrieve that data from the array and inspect the table. I don't have much experience with the VA7000 series, but according to the manual the command is:
armsecure -r -f (filename) -p (password) (array-id)

Re: Win2003 host and San Sufer problem

Arend Lensen — Mon, 29 Mar 2004 07:11:39 GMT

Also check in armdsp -a if secondary path presentation is enabled:

Disable Secondary Path Presentation:__False

regards,
Arend

Re: Win2003 host and San Sufer problem

Mikhail_4 — Mon, 29 Mar 2004 07:37:38 GMT

2 Arend Lensen:
I checked
Disable Secondary Path Presentation:__False
so it's ok

2 Uwe Zessin :
I checked secure table both ways: using Command View GUI and armsecure,
each LUN has 2 table entries:
1 for default (permissions none),
1 for host WWN (permissionos write).
Isn't the way it should be ?
Back to what I said earlier - the same configuration works for the other Win2003 host with the same FCA and drivers