Configuring VIO servers to be VSCSI clients of another VIO server
brian_s 270002K5X3 Comments (5) Visits (8824)
There are a couple of scenario's where this could be particularly useful:
But as you probably know in the HMC GUI it won't allow you to create a "client" adapter in a VIO partition, and it won't allow you to setup a "server" adapter with a VIO partition as a client.
I discovered if you use the HMC command line interface to add the VSCSI adapters, it will actually let you setup a VIO server as a VSCSI client of another VIO server, and even more surprisingly it actually seems to work!
I did run in to issues when trying to virtualize already virtualized resources. For example, it doesn't work to have VIO1(Real resources) serving VSCSI disk to VIO2(all virtual), and the have VIO2 share its already virtual disk resources to an AIX partition (basically disk assigned through VIO1->VIO2->AIX). The VIO2 errpt logged disk/LVM errors and the AIX server had issues with the disk.
This was tested with HMC 126.96.36.199 (an older version..) I'm not sure if it will still work with newer versions of the HMC. Obviously this isn't going to be supported by IBM so only play around with this if you know what you are doing and you are in a TEST environment!
Both the "chsyscfg" (for the profile) and "chhwres" (to DLPAR) worked from this version of the HMC to add a client VSCSI adapter to a VIO server and to add a server VSCSI adapter with a VIO as a client.
If you try it out, post a comment on the blog and let me know what your experience is with it. I just discovered this tonight and haven't done very much testing at this point, but I can already see several scenarios where this could be very useful.