xfb52 at dial.pipex.com
Fri Feb 1 09:36:23 PST 2008
Darryl Hoar wrote:
>>maybe I spoke to soon. While looking at dmesg in prep for doing
>>a custom kernel for my new server, I noticed an oddity.
>>ad4 - DMA limited to UDMA33, device found non-ata66 cable.
>>ad4 - <SAMSUN HE160HJ JF800-24>
>>Is this telling me the system recognized my
>>160GB 7.2K RPM Serial ATA 3Gbps 3.5-in Cabled Hard Drive as
>>a UDMA33 ?
>atapci0: <ServerWorks HT1000 SATA150 controller> port
>3,0xecb8-0xecbf,0xeca4-0xeca7,0xece0-0xecef mem 0xefdfe000-0xefdfffff irq 6
>evice 14.0 on pci3
>ata2: <ATA channel 0> on atapci0
>ata3: <ATA channel 1> on atapci0
>atapci1: <ServerWorks HT1000 UDMA100 controller> port
>177,0x376,0x8c0-0x8cf at device 2.1 on pci0
>ata0: <ATA channel 0> on atapci1
>ata1: <ATA channel 1> on atapci1
>acd0: CDRW <HL-DT-STCD-RW/DVD-ROM GCC-T10N/A102> at ata0-master UDMA33
>ad4: DMA limited to UDMA33, device found non-ATA66 cable
>ad4: 152587MB <SAMSUNG HE160HJ JF800-24> at ata2-master UDMA33
>ad6: DMA limited to UDMA33, device found non-ATA66 cable
>ad6: 152587MB <SAMSUNG HE160HJ JF800-24> at ata3-master UDMA33
>This is the copied relevant portions of demsg's output. I have only used
>list devices, so am basically unfamilar with it.
>So, how do I get the system to recognize the drives as SATA ?
I think you are placing a lot of faith in an error message and that your
drives *may* be being recognised as SATA drives with just something
spurious (in the driver) causing this message to appear. It looks like
the same chipset is providing both IDE/UDMA and SATA, so maybe the
driver is trying them as IDE first, producing the error messages, then
finding they are SATA after all. Just a guess
Have you tried any basic disk benchmarks? Even a diskinfo -t should
show you the kind of throughput your are getting, or something like
dd bs=64k if=/dev/zero of=/some/file/on/the/disk count=10000
That takes ~10 secs on my machine. If your performance is better than
UDMA33 then you could just ignore the message or file an informational
PR (if there isn't one already). Don't forget to be careful about
bits/sec versus bytes/sec UDMA 33 is 33MB/s which is 33*1000*1000 bytes
but 8 times as many bits, which some applications report.
Having failed to get a definitive answer here you could also try the
driver maintainer whom I believe to be sos at freebsd.org. Confirm that
from the manpage and don't forget to mention the version of FreeBSD you
have (6.3?) See also this thread:
On a random SATA150 disk I get ~60017191 bytes/sec for a dd, which ~=
60000 kbytes/sec from diskinfo and ~= 60MB/s or twice UDMA33. I believe
that to be about par for a modern SATA disk.
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