low USB tranfer rate with external IDE

[Vlad Skvortsov]

Vlad Skvortsov wrote:

[skipped]
>
> Ok, I have compiled a kernel with ehci in. Here is a snippet of dmesg 
> output (right after rebooting the box):
>
> da0 at umass-sim0 bus 0 target 0 lun 0
> da0: <Maxtor 6 L250R0 BAJ4> Fixed Direct Access SCSI-0 device
> da0: 40.000MB/s transfers
> da0: 238475MB (488397168 512 byte sectors: 255H 63S/T 30401C)
> umass0: BBB reset failed, TIMEOUT
> umass0: BBB reset failed, TIMEOUT
> umass0: Invalid CSW: sig 0x4628f8ff should be 0x53425355
> (da0:umass-sim0:0:0:0): Synchronize cache failed, status == 0x4, scsi 
> status == 0x0
>
>
> Note that it displays high transfer rate this time. I've ran 'diskinfo 
> -t' to check the actual rate; the seek tests have passed but transfers 
> hung. 'dd' froze either:
>
> 13:31 [vss at bear] ~ > dd if=/dev/da0 of=/dev/null bs=1m count=10
> ^C
>
> Nothing relevant in /var/log/messages. How can I debug it further?
>

By googling around it seems that these messages may indicate a hardware 
(enclosure) problem. Can someone share what IDE USB 2.0 enclosures are 
known to be working OK so that I can rule that possible cause out?

-- 
Vlad Skvortsov, vss at 73rus.com, http://vss.73rus.com