softraid encryption

[Sunnz]

I have been using vnconfig for disk encryption but I am aware that softraid is the new thing for some years, so I decide to try it in a virtual machine before actually using it on my real system. (Is it still "new" or am I just slow?)

Anyway I was able to have encrypted disk (sd1, sd2) created from partitions (sd0j, sd0k) and all is good.

I got some n00bish questions though... I haven't really used raid before...

What is softraid0? Is it just a controller of some kind? I was able to make 2 encrypted volumes both using softraid0 (bioctl -c C -l /dev/sd0j softraid0; bioctl -c C -l /dev/sd0k softraid0; ) but I heard that you can have more... (like softraid1, 2, etc...) but why? Is there a limit or something?

How do to "undo" an encrypted volume? Say I did bioctl -c C -l /dev/sd0j softraid0; and sd0 appears but I want to undo that... is this just something you don't do with a RAID configuration?

Lastly is there a way to create an encrypted volume using a file? Like with vnconfig you can create a sparse disk image as a file like /img/disk.img that have a capacity of 10 GB but only takes up as much disk space as the file inside takes... I have tried to do something like,

mount_vnd /img/test.img svnd0 #no encryption
fdisk -i svnd0
disklabel -E svnd0 # svnd0a is RAID
bioctl -c C -l /dev/svnd0a softraid0
##kernel panic##