Hi Terry and you all,
On Tuesday, 16. April 2002 01:48 you wrote:
> [...]
> As I said: it could be drive settings unrelated to the code
> itself being correct. I've given three suggestions to verify
> this, one way or the other:
>
> 1) Control the drive DMA speed down
>
> 2) Pretend the maximum tagged command queue depth is
> smaller than it is
>
> 3) Toggle the write caching on the drive
I used 'atacontrol' to read the number of tags allowed: it is 31
(0x1F). Perhaps Soren could tell me how to force it to, say, 0x10?
Then I tried various combinations of UDMA100/66/33 and wc=0/1 - it
nearly doesn't change anything. If WC was enabled, I saw errors
concerning tags 0 *and* 1, whereas without write caching only tag=0 was
mentioned. I should say that my simple test was a 'tar cvf /dev/null
/usr/ports' with /usr/ports on an ATA-partition. Why *Write*Caching has
any influence here...???
What was consistent thru all test was, that the disk operates quite
some time until the error occures the first time. After that, it is not
possible to access the disk in UDMA-Mode any more, regardeless *which*
UDMA-Mode it is. 'Quite some time' means approx. 50% of /usr/ports in
the above mentioned 'test'.
After the first switch to PIO4, I umounted the filesystem and switched
back to UDMA33 for instance - I couldn't even *mount* the filesystem
again!
But w/o Tagged Queuing the disk operates flawlessly, so I'm a bit in
doubt, if the errors with WD-disks have the same source... but may be.
So far - but still some data:
CPU: AMD Duron(tm) processor (801.82-MHz 686-class CPU)
real memory = 268369920 (262080K bytes)
pcib1: <VIA 8363 (Apollo KT133) PCI-PCI (AGP) bridge> \
at device 1.0 on pci0
/* It's an EPoX 8KTA2 MoBo */
atapci0: <VIA 82C686 ATA100 controller> port 0xd000-0xd00f \
at device 7.1 on pci0
atapci0: Correcting VIA config for southbridge data corruption bug
ad0: 43979MB <IBM-DTLA-307045> [89355/16/63] at ata0-master UDMA100
...and 'atacontrol cap 0 0' says:
ATA channel 0, Master, device ad0:
ATA/ATAPI revision 5
device model IBM-DTLA-307045
firmware revision TX6OA50C
cylinders 16383
heads 16
sectors/track 63
lba supported 90069840 sectors
lba48 not supported
dma supported
overlap not supported
Feature Support Enable Value Vendor
write cache yes no
read ahead yes yes
dma queued yes yes 31/1F
SMART yes no
microcode download no no
security yes no
power management yes yes
advanced power management yes no 0/00
automatic acoustic management yes no 254/FE 128/80
That's it.
--
Ciao/BSD - Matthias
Matthias Schuendehuette <[EMAIL PROTECTED]>, Berlin (Germany)
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