>
> Hi, im trying to setup and ide software raid, i have 4 IDE drives each
> operating on there own channel (using external hpt-366 chipset controller).
>
> I setup raid5 with 4x5GB partitions i got it working ok, but CPU usage is
> sitting at 30% when im not doing anything.
> Its running on a AMD K6-2 266 128MB ram
>
> Is it normal to have a high CPU usage like this?
hmmm, strange, normally if there is no I/O the CPU usage should be zero,
except if raid5resyncd is resyncing the arraay.
Have you tried to tune each IDE disk with hdparm,
before running the array ?
hdparm -d 1 -m 8
/sbin/hdparm -m 8 -d 1 -c 1 /dev/yourhd
I say this because some distrubutions ( RH 6.0 for example) do not tune
your IDE disks much at startup especially if you have more than one disk.
>
> Also in raid0 mode i got around 25MB/s i had read that with raid0
> performance increased nearly linearly.
> I teasted each drive individually with hdparm -t and the slowest drive got
> 14MB/s so i was hoping i would have been able to get above 40MB/s in raid0.
hdparm is pretty unreliable for testing REAL disk throughput,
use bonnie instead, with a filesize at least 4-5times your RAM
to eliminate caching distortions.
Consider the fact that on IDE 2 disks contends for the same bus
if you run master+slave, and therefore the scalability not linear,
but I can't say how big the impact is.
regards,
Benno.
