[Linux-ha-dev] Hi list!!

[Crispin Cowan]

"Stephen C. Tweedie" wrote:

> Absolutely.  Data journaling is not application journaling.  You can
> ensure that the data is intact on disk, but that doesn't mean that it
> represents a consistent state for the application.  Only the
> application can ever have a hope of understanding what its own
> transaction semantics are.

I am very interested in process checkpoint and rollback.  I wrote my
dissertation and several papers on optimistic programming several years ago (
http://www.cse.ogi.edu/~crispin/hope.html ).  Optimistic programming depends
on being able to checkpoint a process now, and roll back to that state later.

I implemented a crude form of checkpoint and rollback for processes, but
couldn't do anything about rolling back file state.  Can a journaling file
system give me the hooks I need to be able to checkpoint and rollback the
state of one or more files?

Thanks,
    Crispin
-----
Crispin Cowan, CTO, WireX Communications, Inc.    http://wirex.com
Free Hardened Linux Distribution:                 http://immunix.org