Abdul,
The disk group version isn't going to be your problem here. If you're doing block level copy at the volume level, you will need to have your disk group and volumes already created on your new system (with SF 5.0/5.1), so that the block level copy can work between two different volumes. And your new volumes will likely have to be exactly the same size in blocks as your old volumes. So if you create the new disk group and new volumes on the new system, they will work just fine, because they will have been created in SF 5.0/5.1.
Its the file system that's going to present a problem. The file system is contained within the volume. Assuming you are successful at replicating the volume data, block by block, to the new volume, then when you try to mount your file system, VxFS 5.0/5.1 will throw an error, because the file system disk layout version from VxFS 3.2 is much earlier than VxFS 5.0/5.1 can work with. Somehow, you've got to get your old file systems upgraded to a file system disk layout version that is acceptable to VxFS 5.0/5.1.
You'll probably have to do a series of upgrades on your old systems to make this work. You'll have to dig through the old SF Installation Guides, to see what version of SF (after 3.2) can accept and upgrade your existing file systems to an intermediate SF version (maybe 4.1), and then do the same thing again at SF 5.0/5.1. You have to be careful to check the different file system disk layout versions that are compatible with the different versions of VxFS. I would advise you to do this on a test system first. Make sure you have good backups before you begin.
Are you relocating to a new site? Are you also considering dumping your files to tape media and restoring files from tape to the new file systems? This way you wouldn't have to worry about file system disk layout versions.
-John
