How do you number your virtual adapters when you're planning to build a new Power system?
Some people put no thought into their numbering plans; they simply have the system pick the next available adapter number in the HMC GUI. Others just use even and odd numbers -- 10, 20, 30 and 40 from vio1 and 11, 21, 31 and 41 from vio2 -- and then map the next LPAR to the next available number. When troubleshooting is needed, they look to their documentation or employ some other method to figure out which adapter goes where.
I was recently shown a numbering scheme for virtual fibre and virtual SCSI adapters -- 4-digit numbers for fibre and 3-digit numbers for SCSI. The first digit was 1 for vio1 or 2 for vio2. The second digit on the virtual fibre adapter indicated which physical fibre port it was connected to via the vfcmap command.
When using NPIV (see here and here) and runing vfcmap, you indicate the physical FCS device you'll be using for your connection. In this numbering scheme I know the VIO server the virtual adapter is coming from and the physical FCS device it's mapping to. The last two digits indicate the partition ID it's connecting to. (Obviously if your partition IDs extend into 3- or 4-digits, you would modify as necessary for vio3 and vio4.)
For example, on vio1 I might have virtual adapter 1112, and on vio2 I might have 2112. This would indicate the VIO server it came from, the physical device it was using and the LPAR ID, which in this case would be 12. By using the same numbers on both the client and the server, tracking down adapters becomes very simple. Virtual SCSI is the same, only 112 and 212 would be used. This indicates the VIO server it came from and the LPAR ID it was connected to. There would be no need to indicate the physical device it was mapping to.
A scheme like this comes in handy when you're planning server builds that comprise many physical machines and many, many virtual machines. For example, a customer wanted four paths over four virtual adapters into their dual VIO servers, two from each VIO server.
For LPAR ID 10, 1110 and 1210 could be used for vio1, and 2110 and 2210 for vio2. Then for LPAR ID 11, 1311 and 1411 could be used for vio1, and 2311 and 2411 for vio2. This pattern would continue until you ran out of physical adapters; then you would circle back around. For example, if you had the physical fcs0, fcs1, fcs2 and fcs3 adapters on your vio1 server, you might see a pattern like this for the four LPARs with IDs 10, 11, 12 and 13:
Feel free to share your own adapter-numbering scheme in Comments.