I have a problem with iSCSI on AMD64 Xen HVM

Janne Snabb snabb at epipe.com
Sat Feb 12 08:23:44 UTC 2011


Justin,

Thanks for your comments regarding the state of Xen on FreeBSD.

On Mon, 31 Jan 2011, Justin T. Gibbs wrote:

> I sympathize with your desire for more code comments to make it easier to
> ramp up on Xen.  Unfortunately, there is little documentation about Xen
> other than the "Linux reference implementation", and it is usually quite
> terse in the comments department.

This lack of documentation about Xen is the biggest turn-off for
me regarding Xen. I started learning about Xen recently, and was
very surprised and disappointed to notice that there is no real
documentation nor specs about xenbus, xenstore contents, interfaces
to basic devices (like net & blk), etc. I was expecting there to
be more formal documentation available especially given that there
are many big corporate entities involved in Xen. Maybe they have
some internal specs which they are not releasing...

Lack of interface specifications makes it impossible for example
to write drivers which are more or less guaranteed to work with
future versions of Xen as well as the current version. Now the
process of writing anything would be to study/"reverse-engineer"
Linux source code to understand what it does, and then re-implement
the same functionality with new code. Not the best way of doing
things.

Just my thoughts...

--
Janne Snabb / EPIPE Communications
snabb at epipe.com - http://epipe.com/


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