Improving SATA disks performances ?

[Gabriel Labelle]

Hi Alex,

I enabled these settings in /etc/sysconfig/harddisks as you suggested :

But it seems that the best values were already probed on system startup.

Intel PIV 3GHz C (HT enabled)
Asus P4C800-E Deluxe
Corsair TWINX1024-3200LLPRO
2x 74GB SATA WD Raptor 10000 on the Intel ICH5-R SATA controller (IDE
mode) :

/dev/md0 (raid1) -> /boot 
/dev/md1 (raid0) -> /
/dev/md3 (raid0) -> /home

/dev/sda and /dev/sdb are the individual HDD.

Default /etc/sysconfig/harddisks

/dev/sda:
 Timing buffer-cache reads:   3664 MB in  2.00 seconds = 1833.20 MB/sec
 Timing buffered disk reads:  206 MB in  3.03 seconds =  68.09 MB/sec

/dev/sdb:
 Timing buffer-cache reads:   3648 MB in  2.00 seconds = 1825.19 MB/sec
 Timing buffered disk reads:  206 MB in  3.02 seconds =  68.20 MB/sec

/dev/md1:
 Timing buffer-cache reads:   3684 MB in  2.00 seconds = 1843.20 MB/sec
 Timing buffered disk reads:  410 MB in  3.01 seconds = 136.32 MB/sec

/dev/md3:
 Timing buffer-cache reads:   3660 MB in  2.00 seconds = 1831.19 MB/sec
 Timing buffered disk reads:  226 MB in  3.02 seconds =  74.85 MB/sec

Modified /etc/sysconfig/harddisks

/dev/sda:
 Timing buffer-cache reads:   4016 MB in  2.00 seconds = 2009.31 MB/sec
 Timing buffered disk reads:  206 MB in  3.02 seconds =  68.13 MB/sec

/dev/sdb:
 Timing buffer-cache reads:   3820 MB in  2.00 seconds = 1911.25 MB/sec
 Timing buffered disk reads:  206 MB in  3.03 seconds =  68.09 MB/sec

/dev/md1:
 Timing buffer-cache reads:   3896 MB in  2.00 seconds = 1949.27 MB/sec
 Timing buffered disk reads:  410 MB in  3.01 seconds = 136.19 MB/sec

/dev/md3:
 Timing buffer-cache reads:   3652 MB in  2.00 seconds = 1826.28 MB/sec
 Timing buffered disk reads:  226 MB in  3.01 seconds =  74.99 MB/sec

It seems like the /home partition is much slower than / (almost half the
speed). Is it simply because / is at the beginning of the HDD? And is
there something I can do about it?

Many thanks again
Gabriel


On Thu, 2004-08-12 at 16:29, Alexander Dalloz wrote:
> Am Do, den 12.08.2004 schrieb Gabriel Labelle um 15:19:
> 
> > I use the linux soft raid md driver on my system and I would like to make
> > sure I get the best from my hardware.
> 
> > What should I check and/or do (hdparm options, etc.) in order to
> > really optimize disks/raid performances on this FC2 workstation?
> 
> > Gabriel
> 
> Normally the best values are probed at boot up automatically. So no
> manual adjustment with hdparm parameters are necessary. If you like to
> play - and from your RAID0 setup it seems you don't care much about data
> loss - you can try "EIDE_32BIT=3", "MULTIPLE_IO=16", "LOOKAHEAD=1". It
> depends on your specific system whether these settings are already
> active. Set the settings in /etc/sysconfig/harddisks when proofed to be
> good. Take the warning at top of this file serious!
> 
> Alexander
>