In the last episode (Jan 06), Derek Marcotte said:
> Actually, just for kicks:
>
> # dd if=/dev/da0 of=/dev/null bs=128k &
> [1] 1839
> # iostat -K -w 1 da0
> tty da0 cpu
> tin tout KB/t tps MB/s us ni sy in id
> 1 42 64.00 607 37.92 1 0 1 0 98
> 0 43 64.00 222 13.87 0 0 2 0 98
> 0 43 64.00 223 13.92 0 0 0 2 98
> 0 42 64.00 224 13.98 0 0 2 0 98
> 0 43 64.00 222 13.86 0 0 3 0 97
> 0 43 64.00 223 13.92 0 0 1 2 98
> 0 43 64.00 223 13.92 0 0 2 1 97
> 0 42 64.00 223 13.92 0 0 3 0 97
> 0 43 64.00 223 13.92 0 0 1 0 99
>
> Seems to give me the performance that I expect...
Aha. Check the WCE bit to see if your write cache is enabled on the
disk:
# camcontrol mode da0 -m 8 | grep WCE
If it's not set, that could be contributing to the speed difference
between reads and writes. Set it by running "cmcontrol mode da0 -m 8
-e -P 2", and set "WCE: 1".
--
Dan Nelson
[EMAIL PROTECTED]
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