Re: [linux-usb-devel] 2.6.0-test1: random errors for USB disk

[Harald Dunkel <harri@synopsys.COM>]

David Brownell wrote:
> Alan Stern wrote:
> 
>> The information in your system logs is very clear.  Your USB drive 
>> worked just great until it received a big data transfer.
>>
>> Under 2.4, the largest WRITE transfer was 130048 bytes and it worked 
>> fine.  Under 2.6, the largest attempted WRITE transfer was 524288 
>> bytes and it
>> crashed the drive.  The two commands were otherwise identical.
> 
> 
> Just to clarify:  there's another difference, and that's that 2.4 does
> doing that smaller write one page at a time (write, wait, write, wait,...)
> while 2.6 does it all at once (write, write, write, write, ... wait).
> 
> That difference is how I've seen usb-storage top 30 MByte/sec on USB
> with 2.6 kernels, when 2.4 may not reach 10 MB/sec on the same hardware.
> 
I am using the disk in question to do backups of my $HOME. On 2.4.21
it was written with an amazing speed of about 20 MByte/sec, which I had
never expected. I could live with 10, if it is reliable.


Regards

Harri