Question: USB 2.0 failure/timeout with large transfers

Posted by ffirman on Mon 7 Mar 2005 at 23:28

I have found on Kernel's 2.4.27 (debian) 2.4.29 (mepis) and 2.6.10 (mepis), when I try to transfer a large volume of files, with total size about 1G, the usb harddrive, gets reset, and goes off line.

I have to unplug it at plug it back in, and the data I sent is not complete. Only about 300M is there.

This works with vfat, and ext3 formated partitions.

There doesn't seem to be a problem with usb 1.1 speed.

Also if I transfer about 900M of data, sweet. Then leave the drive for a little while (Might be 5 mins, ie when I realise the transfer has finished), I can transfer another 900M ok.

For Testing. The testing was done on Debian unstable (kernel 2.4.27-2-686

I used the following to see how large a transfer could be created:

dd if=/dev/zero of=test1 bs=1024 count=number 

When count=999k the transfer was good

When count=1000k the transfer failed.

(This was both on vfat and ext3).

The second test I did was, how soon can another transfer be done and succeed, for this I used

for ((x=1;x < 4;x++)) ; do dd if=/dev/zero of=test$x bs=1024 count=999k ; sleep 1 ; done

That worked fine.


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