writing to 3ware escalade uses up 100% cpu time in system.
dwhite at gumbysoft.com
Fri Jan 9 15:24:31 PST 2004
On Fri, 9 Jan 2004, Klaus Robert Suetterlin wrote:
> I'm using a 3ware 8506-4LP controller with 4 250GB harddrives in
> Raid 0. All space is in a single slice, separated into 1GB swap and
> the rest into twed0s1d which is mounted under /space...
> When I do
> ``dd if=/dev/zero of=/space/test bs=1000000 count=10000''
> the twed0 maxes out at 70MB/sec and (according to systat) 70% usage.
> Unfortunately my system goes to 100% cpu usage at the same time.
What speed of bus is the 3ware attached to?
You might run 'systat -vmstat 2' and check the amount of CPU going to
interrupts. I suspect you're maxing out on the interrupt handler. Also
look at the # of interrupts to the twe.
> I would really love to be able to use the aproximate 100MB/sec at
> 100% usage of the twed0, without using all that much cpu.
What kind of workload are you expecting to put on? Its very, very rare
that you would be getting large sequential writes like those you are
getting with dd.
Doug White | FreeBSD: The Power to Serve
dwhite at gumbysoft.com | www.FreeBSD.org
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