UFS2 Snapshots in 6.1-Beta4 - Confirmed Problems

[Kris Kennaway]

On Tue, Mar 21, 2006 at 11:40:44AM -0800, John Kozubik wrote:
> 
> 
> On Tue, 21 Mar 2006, Kris Kennaway wrote:
> 
> > > This next one is complicated, and I haven't submitted a PR for it yet, but
> > > I believe it is quite serious for reasons I will expand on below.
> > >
> > > The problem is:  If you completely fill a filesystem (109% usage in `df`
> > > on most systems) that has a snapshot on it, the system becomes very
> > > unresponsive - all interactive and disk response lags terribly and,
> > > although the system is not hung, it is in many cases unusable.
> >
> > Yes :-( This will probably not be fixable in time for 6.1, but
> > hopefully it will be addressed in the future.  FYI, the system may
> > also panic in this situation.
> 
> 
> Because my original description of this behavior was so vague, I was going
> to try to reproduce it again with more details, however it sounds like you
> have already witnessed this and know more about it than I do.
> 
> Is that true ?  Can I skip a few hours of trying to reproduce this ?

Yes, I'm easily able to reproduce it, and I'm told that fixing it will
require fairly extensive work & testing.

Kris
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