Re: Obciazenie dyskow i system

[Marcin Owsiany <porridge@debian.org>]

On Fri, Feb 21, 2003 at 04:36:55PM +0100, Andrzej Wolski wrote:
> 
> Witam, 
> 
> w czasie kopiowania pomiedzy dyskami obciazenie sytemu siega 99% i to
> niewazny czy dysk jest glownym systemu czy innym. Czy da sie to jakos
> zoptymalizowac? 
> 
> n# hdparm -Tt /dev/hdb2
> 
> /dev/hdb2:
>  Timing buffer-cache reads:   128 MB in  5.03 seconds = 25.45 MB/sec
>  Timing buffered disk reads:  64 MB in 67.19 seconds =975.38 kB/sec

$ man hdparm
[...]
    -m     Get/set sector count for multiple sector I/O  on  the  drive.   A
           setting  of  0  disables this feature.  Multiple sector mode (aka
           IDE Block Mode), is a feature of most  modern  IDE  hard  drives,
           permitting  the  transfer  of multiple sectors per I/O interrupt,
           rather than the usual one sector per interrupt.  When  this  fea-
           ture  is  enabled, it typically reduces operating system overhead
           for disk I/O by  30-50%.   On  many  systems,  it  also  provides
           increased  data  throughput  of  anywhere  from  5% to 50%.  Some
[...]

U mnie spadło do 0, chociaż szybciej wcale nie jest...

Marcin
-- 
Marcin Owsiany <porridge@debian.org>             http://marcin.owsiany.pl/
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