Re: geom_sched usage

On Tuesday 19 October 2010 10:18:24 Luigi Rizzo wrote:
> On Tue, Oct 19, 2010 at 08:07:54AM +0200, David Naylor wrote:
> > Would there be any interest in having a rc.d/ script?  I would find it
> > conveniant to specify a single rc.conf line and get scheduling for all my
> > devices.  PC-BSD might find such functionality useful.
> > 
> > See attached for my first draft at such a script, I'm willing to hash it
> > into shape.
> 
> it would surely be useful but try to keep it simple and user-driven
> (this is a general comment on rc.d scripts).
> Some things i think you should simplify in your script:
> - remove support for guessing which devices should get the scheduler.
>   This is really a user decision and if the user names no devices then
>   i believe it is better/safer not to install any scheduler.

I agree but I do think there is a case for an 'ALL' command as the user may 
want scheduling on newly attached devices without knowning their device names 
(i.e. attached USB storage devices).  

I would also like to add a ``gsched_nodev'' that allows one to use 'ALL' 
without having to apply gsched to everything.  

See attached for a devd.conf file that add supports for that.  

> - use standard names such as gsched_flags or gsched_flags_${dev} to hold
>   generic and specific flags for the insert command.
>   It is neither useful nor flexible to have the script insert '-a'
>   in front of the algorithm;

I've changed the variable names.  See attached for the rc.d script.  

_at_Miroslav: thanks for the tip