Sounds to me like your device works fine. It also sounds like the transfer is taking place at USB 1.1 speeds, which is not surprising. If your device is USB 2.0 compatible, more than likely you are NOT getting USB 2.0 speeds.
I have dealt with this issue before, and I am left with the impression that USB is still immature in Linux. Warren -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Thursday, April 08, 2004 10:22 AM To: [EMAIL PROTECTED] Subject: [Linux-usb-users] slow file cp onto USB drive Importance: Low I am having problems copying large files (>400MB) from an ext3 linux (Red Hat) filesystem onto a USB device (Maxtor external hard drive) formatted with a vfat filesystem. The kernel version is 2.4.21-4 (Red Hat Enterprise Linux 3.0 ES). I am using the cp command to do the copy. Smaller files copy as expected. The USB device is mounted read/write with uid and gid set to a specific user. I have been using an 888MB file as a test file; when I try to cp this file onto the USB device, the command locks up and does not return (I've waited > 2 hours); in fact, the entire machine locks up, and I am not able to establish another login session, not even as root from the console. Other existing sessions also freeze. The var/log/messages files doesn't provide any helpful messages. I have tried copying the same 888MB file within the same linux ext3 filesystem, and it works as expected (I think this tells me that cp is OK, that the ulimits are OK, and that the file is OK). The USB vfat filesystem I am trying to write to is 30 GB in size, with approx 22 GB free space. I then tried using rsync with the stats/progress flags; It worked, but was excruciatingly slow; rsync reports transfer stats every few seconds while copying; the intitial rate was between 10 - 20 MB/sec, but it began to slow down around the 400MB mark, and became progressively slower; by completion, it was down to 700kb/sec. It took about 30 mins for the 888MB file to complete copying. I also monitored "top" output during the rsync copy. This machine has 2.5G ram and 4G swap; top shows no swapping and a very slight increase in memory usage, but the %iowait increases to 99% at about the same time the rsync transfer rate begins to decline. To me, this suggests some type of buffer-full effect; I have not been able to determine if the USB device has a write buffer or not. Can anyone suggest what to try next? The USB device needs to be vfat because it is being used to transfer files to windows. Apologies for the long post, and thanks to any responders. ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id70&alloc_id638&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
