DragonFly kernel List (threaded) for 2006-09
Re: Cache coherency, clustering, and Kernel virtualization
:So how does Userland VFS and ZFS go into this?
Userland VFS needs to use SYSLINK. Making progress with SYSLINK
requires a fairly quick development cycle, one that I am not achieving
with the current kernel build/install/reboot cycle. It just takes too
long, even with VMWare.
So far I've been able to commit the basic syslink pipeing technology
and the basic CCMS range lock, and I do consider those to be achievements,
but both took considerably longer then they should have and it was
mostly due to the development cycle. The next stage for both subsystems
is going to be a lot more complex.
It's going to get even worse with the clustering work. There we aren't
talking about a single machine any more, we are talking about multiple
machines tied together in a cluster over a network. I don't want
to imagine what the development cycle is for that using real systems
With kernel virtualization the development cycle is about 10 seconds.
I'll be able to create a 'cluster' with a simple script that runs a
couple of virtual kernels, and destroy it simply by hitting ^C, and
I'll be able to test userland VFS as it will actually be coded in
the kernel and in userland. And if I crash a 'kernel' I won't have to
deal with it writing to swap, or remote gdb, or any of that junk.