On Tuesday 01 January 2002 11:23 pm, Barry Lind wrote:
> Tom,
>
> The platform is Redhat 7.0 with a 2.2.19 kernal.
Is this and IDE based system? If so do you have the drives running in DMA
mode?
What are the results of "/sbin/hdparm /dev/hd(?)" (a,b,c,d ... which ever
drive you are running the database on.)
The 2.2 linux kernel defaults to DMA off. You can try to enable dma by
issuing /sbin/hdparm -d1 /dev/hd(?) You can also test the disk speed with
/sbin/hdparm -tT /dev/hd(?).
In my experience enabling this feature can make a huge improvement in I/O
intensive applications. Other options can help also, but I find dma to have
the largest impact. I find linux almost unusable without it.
