[linux-lvm] Apparent performance degradation for each PV with striping

[Oleg Volkov]

Donald Thompson wrote:

> dd if=/dev/ide/host0/bus0/target0/lun0/disc of=/dev/null
> gave me around 5500 blocks read per second.
>
> lvcreate -i4 -I4 -L somesize vgname -n lvname
>
> My system:
>
> Linux 2.4.2
> Libc 2.1.3
> Debian Potato
> LVM 0.9.1_beta6 utilities and patch.
> ATA 100 IDE interfaces on MB
> idebus set to 66 in /etc/lilo.conf
> CPU is Athlon 1000mhz thunderbird
> 256 megs of RAM
>
> -Don
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm

80G disks may be IBM or Maxtor disks ( right ? )
I had experience with IBM disks. A good stripe
size for them is 64k. I don't know about Maxtor disks
but you can play with stripe size around 64k also.

Basically 64k is a DMA buffer size and should be good.

So try to use -I64 not -I4.


--
Volkov Oleg
BitBand Technologies Ltd.
http://www.bitband.com