Messages in this thread | | | Date | Mon, 13 Feb 2006 12:29:18 +1300 | From | Sam Vilain <> | Subject | Re: [Devel] Re: swsusp done by migration (was Re: [RFC][PATCH 1/5] Virtualization/containers: startup) |
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Vasily Averin wrote: >>When checkpointing it is important to preserve all state. If you are >>doing transparent highly available computing, you need to make sure all >>system calls get the same answers in the clones. So you would need to >>virtualise the entropy pool. > From my point of view it is important to preserve only all the determinated state. > Ok, lets we've checkpointed and saved current entropy pool. But we have not any > guarantee that pool will be in the same state at the moment of first access to > it after wakeuping. Because a new entropy can change it unpredictable. > Am I right?
Good point.
In general this comes under the heading of "when doing highly available computing, ensure each of your computing replicas get exactly the same inputs and always double-check their outputs".
There are lots of 'inputs' that affect the state of the system; when I referred to "/dev/random and the system clock", I was figuratively referring to these. Others might include timing of disk IO events, for instance.
I'd rather not discuss this too much; it was intended to be a flippant "wishful thinking" thought, and is certainly not something I have spent the necessary time investigating to discuss well :).
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