[mensreaj]

Hi all,

Is it possible to connect multiple client LPARs to the same virtual scsi adapter (residing on the VIO servers)? The reason why I ask is that today I ran into the following:

• We have 2 VIO servers.
• On each VIO server, I created a virtual scsi adapter.
• On a client LPAR, let's call it LPAR1, I added 2 client adapters pointing to each of the adapters created on the VIO servers.
• On each VIO server, I created a volume group.
• On each VIO server, inside the volume group, I created a 20G LV.
• I then made the LVs a scsi device.
• I booted LPAR1 off of NIM and was able to install AIX on the 2 newly created disks.

OK, that worked fine.

• I then created a second client LPAR, let's call it LPAR2.
• On LPAR2 I added 2 client adapters pointing to the same server adapters above.
• On the VIO servers, I made 2 vhdisks out of a 2 hdisks.\

Now, when I boot LPAR2 off of NIM, it cannot see the disks. However, if I go back to LPAR1 and run cfgmgr, it sees the disks right away.

So, to work around this, I created 2 new server adapters on each of the VIO servers (which created vhost1) and made the vhdisks using that vhost. I then deleted the existing client adapters on LPAR2 and created two new client adapters pointing to the new server adapters. I then boot LPAR2 off of NIM and it sees the disks no problem.

Should I have been able to use the existing server adapters to see the disks or not?

To note, on both client LPARs, they are using the same SEA that I created on the first VIO server which I find interesting.

Thanks in advance!

[mshulman1980]

If you have dual VIO servers then you can not format and parition the disks that are shared. As of 1.3.0.1FP8, only whole RAW disks can be shared in a dual VIO environment.
You may be able to find a workaround using HACMP.
There are advantages to handing out only whole disks from a performance perspective.
Typically each LPAR needs its own vscsi adapter.
One workaround to this if you absolutely need to slice up your disks is to roll back to a single VIO setup. I've seen one organization I worked for go as far as treating both of the VIO servers as standalone devices from both a SAN zoning perspective and from the frame itself. The result was generally having to do everything twice, and then at the client level the vdisks had to be mirrored. It was not pretty, stale disks were a very common problem, and I would not recommend it to anyone.

[rgbeard]

Review the VIO Redbooks. You don't do LVs, you present HDisks. Also you must go through the steps to turn off SCSI reserve.

[mensreaj]

Hey guys, I don't think I wrote my initial post very well. What I was trying to do was be able to see the same disks that were being shared off of one vhost on a VIO server to multiple client lpars. Through all my tests, I am not able to. To workaround this, I've created extra scsi server adapters and then I've created the target disks on each of the server adapters. Now on the client side (once a client adapter was created pointing to the relevant server adapter), I am able to varyon/varyon vgs from different clients.