rockyhotas It's in the beginning of my message:
rockyhotas After partitioning a new disk with MBR, creating two primary partitions, I was trying to define a disklabel in each of them. Quite soon I realized it was not possible.
But, that's a pretty standard use-case, right?:
1. VFAT (C:)
2. Linux (/)
3. NetBSD (disklabel)
4. OpenBSD (disklabel)
Now, you have 2 disklabels on the disk.
And, if the above is possible (and it is), then this should be possible also (also a common use-case):
1. Linux (/)
2. NetBSD (RELEASE: disklabel)
3. NetBSD (STABLE: disklabel)
4. NetBSD (CURRENT: disklabel)
Notice that to install more NetBSD partitions, I have chosen to remove the VFAT partition.
Now we have 3 disklabels. The logic is straight-forward: if one disklabel can be created inside an MBR partition (and no doubt you can do this), then it should also be possible to create disklabels inside other MBR partitions.
Edit: to be honest, I haven't tried to do this myself, but, it seems like it should be possible. We'll see.