Re: faster boots?

Pavel Machek
2002-04-08T09:55:28Z

Hi!

> > > I'm curios, how much work can you accomplish on your laptop
> > > without any disk access (but you still need to save files - keeping
> > > them in buffers until it's time to actually write them).
> >
> > Debugging session (emacs/gcc/gdb) for half an hour with disks stopped is
> > easy to accomplish.
>
> My suggestion was: there should _never_ be dirty blocks for disks that
> are not spinning. Flush all dirty buffers before spinning down, and spin-up
> on any operation that writes to the disk (and block that operation).

And your suggestion is useless because disk will be up all the time on
the system...

> The opposite to that (which I do not like) processes create as many
> dirty buffers as they want and disk spins up only on sync() or when
> the system is starving for usable memory.

...which is usefull, OTOH. If you have laptop with battery and
suspend-to-disk capability in BIOS when battery goes low, you can
cache for *long* time.

> An aletrnate ides (more drastic) is that fle systems can mount internally
> read-only when a disk is spinned-down. Means - you cannot spin
> down when there is a file handle open for writing. Other than this there
> are advantages.

Hah, so you can never spindown because /var/log/syslog is opened for
writing.

Pavel
--
Casualities in World Trade Center: ~3k dead inside the building,
cryptography in U.S.A. and free speech in Czech Republic.