XServe Raid and QLogic Switch

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Level 1

34 points

XServe Raid and QLogic Switch

First off, I have no idea what any of this stuff does.

Okay, now that that's out of the way...

I have an XServe Raid divided into 4 partitions. Three computers connect to it via a QLogic San Switch 5200. Computer1 sees two partitions. Computer2 sees one partition and computer3 sees one partition.

Computer1 still sees both of it's partitions but Computers 2 & 3 cannot see their partitions.

Now, I think the problem is with the switch. The XServe seems to be fine from everything I can tell.

I've tried troubleshooting the switch but can't even connect to it. All of this to just let you guys know what's going on.

At this point I just want to get my video files off of the XServe partitions that can't be seen so... my question is this:
If I remove the switch from the equation and just plug the XServe directly into the back of my G5 will all four partitions show up so I can get this data off?
I just don't know enough about these things to know what would happen if I did that and want to make sure that nothing strange will happen!

Any advice you guys can give would be SO much appreciated.

Kip

Dual 2 GHz G5, Mac OS X (10.4.11)

Posted on Feb 9, 2010 2:49 PM

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Answer 1

Camelot

Level 9

58,593 points

Feb 10, 2010 6:43 PM in response to Kip G

There are two ways the RAID can be configured in the way you describe. Without knowing which one you're using it's hard to tell you how to 'fix' it.

The first option is that the fiber channel switch is using zoning to restrict which ports can connect to which device. If this is the case, you'd either need to edit the zone setup in the switch or connect one device to a different port. If you try the latter and see a different set of RAID volumes (or none at all) then this is likely to the setup you're using.

The second setup is called LUN masking and is where the XServe RAID itself controls which device can see which RAID volumes (called LUNs). In this case the XServe knows that a specific fiber channel card can see a specific RAID volume. In this case, switching cables won't make any difference.
To change this you'll need to use RAID Admin to manage the XServe RAID itself. Under the Advanced tab you'll find LUN masking and here's where you'll see the RAID volumes and the fiber channel ports that can see each volume. Either disable LUN masking or edit the access list so that some other machine can see the volumes in question.

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Answer 2

Kip G Author

Level 1

34 points

Feb 15, 2010 12:44 PM in response to Camelot

Camelot,
This post totally helped me fix the problem. I had no idea what LUN masking was and when I saw that section in the RAID admin I didn't click it because not knowing what it was I didn't want to accidentally mess anything up. So yeah, I plugged the raid straight into the computer using the copper fibre channel cables and only saw two of the 4 partitions or I guess "slices." So, that made me think that your idea of the LUN masking option was probably right!

I went to that area and yes, it was all set up with various ports seeing certain slices etc. I was able to go around to the two new computers and find their World Wide Port Names and assign those to specific slices. I'm so happy and I've learned all kinds of new stuff!

Something I do think is odd...
We replaced two computers that were connected to the XServe Raid and just took the fibre cable from the old and plugged it into the new. This of course is where the problem came in because the cards in the new computers have different WWPNs than the old. The funny thing is, it worked for a while. The drives showed up on the new computers... until we took a power hit and the XServe powered off and then came back up. So, it's like it doesn't look at the port name while it's on.. just when it first turns on. So it didn't seem to notice that the port names had changed until then.
Seems kinda odd to me but.. hey, it all seems to work!

So yeah, thank you so much. I've learned a lot here!

😀

Kip Gordon
Memphis, TN

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