Re: blktap2 implementation in NetBSD

[Roger Pau Monné <roger.pau%entel.upc.edu@localhost>]

> I was making more of a general observation about netbsd-iscsi-initiator and
> such like rather than specifics of how it might work within Xen. Obviously
> the more flexible the better as one might want to deal with qcow2 files from
> NetBSD in general.

You where right, because block devices cannot be implemented inside
FUSE, you can create a block device, but operations with block devices
are handled directly by the kernel, never passed to the filesystem
driver, so although I can create a block or character device, only
major and minor numbers are read, and I never get the actual
read/write operations on the block driver. The only option to create a
virtual block device is to use a regular file inside a virtual
filesystem and mount it using vnd, which seems overly complicated. The
most interesting part about FUSE was to be able to create a "standard"
implementation, that could be shared amongst other OSes supporting
FUSE.

> It's actually part of the Google Summer of Code:
> http://blog.netbsd.org/tnf/entry/netbsd_s_google_summer_of
> http://www.mail-archive.com/netbsd-soc-cvs%lists.sourceforge.net@localhost/msg02811.html

What do you think about this Manuel? It's worth to implement something
like blktap using libvdisk or FUSE+vnd?

Regards, Roger.