Klaus Schroer <[EMAIL PROTECTED]> wrote:
> (scsi0) Wide Channel, SCSI ID=7, 32/255 SCBs
> (scsi0) Downloading sequencer code... 374 instructions downloaded
> scsi0 : Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) 5.1.20/3.2.4
> <Adaptec AHA-294X Ultra2 SCSI host adapter>
There must be a detection line per disk drive. This is just the aic7xxx header.
> You are right those are 7200RPM disks.
so, with four old 7200 RPM drives (each doing 10 MByte/s), you get
from 26 to 28 MByte/s I/O, with RAID5, this is already quite good.
> We used a blocksize of 4096B and a chunksize of 32kB. Sometimes you can
> see that people suggest a chunksize of 128kB. Is that actually helping?
I personally usually use 4 kb chunksize.
> All the partitions were last on the disk (that means the last 8GB of the
> 18GB drives) but the disk was empty during the test so the files will
> probably be somewhat in the center.
This explains why a not too old 7200 RPM drive only does 10 MByte/s
(DDRS does 13 at the beginning). I have no experience with DORS, however.
