Jorgen Lundman <lundman@lundman.net> writes:

> To which they have an "if vndsimple(bp->b_dec)) { " to test whether or
> not it should use the new method. (Which appears to be an &0x80 test).

The man-page usually helps.

     "There are two variants, the traditional vnd that
     bypasses the buffercache and thus is suitable for swap on files, but not
     for building disk-images, and the svnd ("safe" vnd ) variant that goes
     through the buffercache, thereby maintaining cache-coherency after the
     block-device is closed which makes it suitable for creating disk images.
     The latter is not good for swapping on, though."

//art