Intrepid: Ubuntu has severe problems when using two USB HDDs at the same time

please attach your dmesg log

I've tried this recently with 2 external disks (one fat32 and one XFS, built in ext3+xfs) and copying from one external disk to the other was fast and without any IO errors.
Using jaunty

Sorry but I have already rebooted so dmesg is empty.

Usually I would say that the information that some Alpha developer version of an OS did not produce the errors reported on the most current stable version when testing one time in one special setup is not too helpful. No offence intended of course.

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please answer these questions:

* Is this reproducible?
* If so, what specific complementary steps should we take to recreate this bug?

This will help us to find and resolve the problem.

You can learn how to give us more valuable info on this page : https://wiki.ubuntu.com/DebuggingRemovableDevices

> * Is this reproducible?

Yes.

> * If so, what specific complementary steps should we take to recreate this bug?

Maybe you could do your own test, using an average notebook, big files and two average NTFS formatted USB HDDs. I have encountered similar problems in the past, and my feeling is that this has something to do with Ubuntu's NTFS write support. Sorry if this sounds more than vague.

what CPU do you have?
NTFS-3G is quite heavy on CPU, so that could be it.

MacBook Pro rev. 3. Intel Core 2 Duo 2.20 GHz.

Just read that I/O errors can be caused by hardware, too (http://www.ntfs-3g.org/support.html#ioerror). In the meantime, my proposal for discussion would be that Ubuntu provides a more detailed error message on the GUI. As I read in http://www.ntfs-3g.org/support.html#ioerror, Ubuntu logs everything important in this context anyway, so the information is actually there.

Well i haven't asked without testing first, and can't see this issue with my two passport usb HDD (ntfs for both) on my laptop ( Acer 1692WMLi pentium M 1,73GHz with 1GiB of ram on Ubuntu 8.10).

Can you try on a 32bit Intrepid Ibex to see if this is not a 64/32 bit problem ?
Can you try on another hardware ?
Can you also reproduce this issue and give us your dmesg like asked before and other informations like discribed on this page https://wiki.ubuntu.com/DebuggingRemovableDevices ?

For improvements in the messages returned by ntfs-3g, it's better to open an another report to ask them.

Tanks

I'm very sorry to say that I just reproduced something very similar to this.
Copying files from an external disk (in FAT32) to a 16GiBs USB pendrive (also in FAT32) slows down to something close to 2MiB/s.

$ uname -a
Linux blubug 2.6.28-11-generic #41-Ubuntu SMP Wed Apr 8 04:39:23 UTC 2009 x86_64 GNU/Linux

$ cat /proc/version
Linux version 2.6.28-11-generic (buildd@crested) (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #41-Ubuntu SMP Wed Apr 8 04:39:23 UTC 2009

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=9.04
DISTRIB_CODENAME=jaunty
DISTRIB_DESCRIPTION="Ubuntu jaunty"

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=9.04
DISTRIB_CODENAME=jaunty
DISTRIB_DESCRIPTION="Ubuntu jaunty"

$ sudo fdisk -l
Disk /dev/sdb: 16.0 GB, 16064184320 bytes
5 heads, 32 sectors/track, 196096 cylinders
Units = cylinders of 160 * 512 = 81920 bytes
Disk identifier: 0x00000000

   Device Boot Start End Blocks Id System
/dev/sdb1 51 196096 15683648 c W95 FAT32 (LBA)

Disk /dev/sdc: 640.1 GB, 640135028736 bytes
255 heads, 63 sectors/track, 77825 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x1188663d

   Device Boot Start End Blocks Id System
/dev/sdc1 1 77825 625129281 c W95 FAT32 (LBA)

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.