md devices mounted with async

[Kris Kennaway]

RW wrote:
> mdmfs(8) has an example of a malloc-backed md device mounted with the
> async option. Is there any point in doing this with malloc and vnode
> devices? In neither case does a write to the file-system require a write
> to a physical disk.

Well, for vnode devices it does write to the disk, but that isn't the 
point; in both cases you are writing to the filesystem that is mounted 
on top of the md, so that will be faster if it is mounted async.

Kris