Re: [git patch] libata resume fix

[Bill Davidsen <davidsen@tmr.com>]

Jens Axboe wrote:

> On Wed, May 31 2006, Robert Hancock wrote:
>  
>
> > Bill Davidsen wrote:
> >    
> >
> > > The trade-off is that if I have a 15k rpm SCSI drive, it would take a 
> > > lot of design changes to make it spin up quickly, and improve a function 
> > > which is usually done on a server once every MTBF when replacing the 
> > > failed unit.
> > >
> > > I think the majority of very large or very fast drives are in systems 
> > > which don't (deliberately) power cycles often, in rooms where heat is an 
> > > issue. And to spin up quickly take a larger power supply... 30 sec is 
> > > fine with most users.
> > >
> > > Couldn't find a spin-up time for the new Seagate 750GB drive, but the 
> > > seek sure is fast!
> > >      
> > I wouldn't guess that even a 15K drive would take nearly that long. For 
> > boot time on servers it doesn't matter much though, disk spinup time is 
> >    
>
> I do use a 15K rpm drive in my workstation (hello git!), and the spin up
> really isn't that bad. Less than 10 seconds for the actual spin up, I
> would say.
>  
Sounds about right, but clearly longer than the 2 sec mentioned early in 
this thread. I think a long delay is okay as long as it gets stopped 
when the drive does come ready.

>  
>
> > in the noise compared to the insane BIOS delays on most of them during 
> > bootup. Like on some servers (ahem.. IBM) which have about a 15 second 
> > delay on the main BIOS screen, 10 second delays on every network boot 
> > ROM, a 1 minute delay on the SCSI controller before it even starts 
> > scanning the bus, then another good 10 seconds before it starts booting. 
> > Gets annoying after a few reboots..
> >    
>
> Indeed, the BIOS bootup time on servers is typically anywhere from
> really bad to truly awful.
>
>  
I try *very* hard not to do bootup on servers, the paperwork involved 
with an outage takes longer than the boot time ;-)

--
bill davidsen <davidsen@tmr.com>
 CTO TMR Associates, Inc
 Doing interesting things with small computers since 1979

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