Disk Enclosures
cancel
Showing results for 
Search instead for 
Did you mean: 

VA7400 How to Find Out Which Disk Belongs to Which RG?

SOLVED
Go to solution
Michael Gretton
Frequent Advisor

VA7400 How to Find Out Which Disk Belongs to Which RG?

I have been asking many questions. Sorry. I am almost there with my va7400.

I have 2 brocade switches. One of my controllers for my VA go to one switch and the other goes the other switch. In SAM I see each lun that I have created in Command View twice. I have had great help from this forum on how to tell which controller is which and I am able to understand the hardware paths fairly reasonable.

I created six LUNs in command view. I assigned every other LUN to RG1 and the others to RG2. I now want to create my volume groups for oracle and my logical volumes. I see my 6 LUNs as 12 LUNs. Six going to controller 1 and six going to controller 2. When I create a logical volume on my server, I obviously want to use the proper primary path for my LUN. How can I tell on my server which LUN is matched to which RG? This is so confusing and I am going through messages and PDFs and I am not getting it. I can see clearly the different controllers and how that works, but how do you know when you are creating your volumes - which LUN is assigned to which controller?

Please help!

Mike
5 REPLIES
Eugeny Brychkov
Honored Contributor
Solution

Re: VA7400 How to Find Out Which Disk Belongs to Which RG?

Mike, read this.
VA7400 has 2 controllers. By default C1 owns disks in odd slots (RG1), and C2 owns disks in even slots (RG2). LUN can be created only within RG, either RG1 or RG2. There's N-way bus (internal) between controllers so each controller can see LUNs other controller "owns".
So, if you have (as I see) classic HA configuration, you should see each LUN twice: example: through controller C1 you see LUN created in RG1, but second path is through controller C2 and N-way bus (to controller C1).
BUT this is the same LUN with same information on it. If you created 3 LUNs in RG1 and 3 LUNs in RG2 there are 6 LUNs in VA and you should see all them twice - 12 LUNs. AND as you have 2 paths to each LUN you should set-up alternate paths in LVM to each of 6 LUNs. After doing it you should see each of 6 LUNs only one time. That's normal 'layout'.
About assignment: BY DEFAULT controller C1 owns LUNs in RG1 and C2 owns LUNs in RG2. In case path to C1 fails alternate path to C2 is used, and, internally to VA, data is transferred to C1 and then to owning disks/LUNs. But if C1 fails C2 takes ownership of LUNs C1 owned... See difference?
I hope I answered your questions. If not, post more.
Eugeny
Ian Hillier
Frequent Advisor

Re: VA7400 How to Find Out Which Disk Belongs to Which RG?

The last number in the device path is your LUN number. For instance, the device path 0/7/0/0.1.18.39.0.0.2 coincides with LUN 2. Look in CommandView to see which RG you put LUN 2 in. 7 is the HBA slot number from the server and 18.39 is the array controller number but I'm not sure how to tell which is which. If you use SAM, it picks the primary path for you and you'd have to test to see if you pick LUNs from different RGs if SAM picks different primary paths.

Regards,

John
Michael Gretton
Frequent Advisor

Re: VA7400 How to Find Out Which Disk Belongs to Which RG?

Thanks guys. Eugeny: your explanation was excellent.
Insu Kim
Honored Contributor

Re: VA7400 How to Find Out Which Disk Belongs to Which RG?

To delete a LUN on the front panel,

1. Select the Logical Drv Changes from the main menu.
2. Select Delete L-Drv.
3. Select a drive number 0 to 7.
4. Select Confirm.

Hope this helps you.
Never say "no" first.
Eugeny Brychkov
Honored Contributor

Re: VA7400 How to Find Out Which Disk Belongs to Which RG?

Insu, this question is about VA7400, not about Autoraid 12h :o) If talking about autoraid then you're absolutely right - this is the simplest way to remove LUN
Eugeny