Re: New filesystem for Linux

[Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>]

> > > > new method to keep data consistent in case of crashes (instead of
> > > > journaling),
> > >
> > > Your 32-bit transaction counter will overflow in the real world.  It
> > > will take a setup with millions of transactions per second and even
> > > then not trigger for a few years, but when it hits your filesystem,
> > > the administrator of such a beast won't be happy at all. :)
> >
> > If it overflows, it increases crash count instead. So really you have 2^47
> > transactions or 65536 crashes and 2^31 transactions between each crash.
>
> I am fully aware the counters are effectively 48-bit.  If they were
> just 32-bit, you would likely have hit the problem yourself already.
>
> Jörn

Given the seek time 0.01s, 31-bit value would last for minimum time of 248 
days when doing only syncs and nothing else. 47-bit value will last for 
reasonably long.

Mikulas