VIMAGE status

Julian Elischer julian at
Sat May 2 17:21:47 UTC 2009

The VIMAGE code is nearly all in the the kernel.

One is now able to make VIMAGE kernels (add options VIMAGE)
though they don't actually allow you to make multiple
vimages instances yet..

The VIMAGE option enables all the low level changes needed
throughout the kernel.

The VIMAGE_GLOBALS option basically sets thing sback to how they were 

Having neither (the default) gives a kernel that is a kind of hybrid.

The Hybrid state is what will go forward as 'NON-VIMAGE' mode
and the VIMAGE_GLOBALS mode will probably go away in time as
it complicates the code.

The aim of this mail is to ask people to try add the VIMAGE option
to their regular kernels and try use them as you woudl normally.
You will not yet be able to use any new VIMAGE features but we
should be fully compatible with previous kernels.

Please report any concerns to the freebsd-virtualization@ mailing list.

THEORETICALLY you should not see any changes in behaviour, however we 
have the following issues:

* SCTP is not fully converted yet. add 'nooptions SCTP' for now if you
   are not using it yet.

* An NFS (crash) issue was reported. This MAY have been fixed...

Theory tells us that all three kernel options should behave about the 
same but if you do try this, and have any benchmarking facilities,
it would be incredibly useful if you could let us know if you see any 
performance changes between the three.


Julian (currently running a VIMAGE kernel myself)

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