On Mon, Jul 05, 2004 at 05:01:04PM -0400, Charles Panzarella wrote:
On Mon, Jul 05, 2004 at 03:07:45PM -0400, Charles Panzarella wrote:
I have an external USB 2.0 hard drive (buslink) that seems to not be running at its fastest possible speed in Suse 9.1. When copying large files from the drive, I get a maximum throughput of only about 1 MB/s. I had the same problem in Suse 9.0, and I had apparently fixed it by adding the async option to the entry in my fstab file. With that option, I was then able to acheive transfer speeds of up to about 7 MB/s. This seems to be true of any USB hard drive I use. The problem is that since there is no entry in the fstab file for the usb hard drive because of the new subfs system, I can no longer easily add the async option. I tried editing the hotplug.subfs.functions file to add the async option manually in there, but when I do so, it seems to not have the same effect as before (transfer speed is still slow).
So, I have a couple of questions. First, why are usb drives so slow by the default settings in suse, and is there another way of achieving trues USB 2.0 speeds without adding the async option. I have not seen another way of doing it. Second, if async is the only way to go, why is it that this option no longer seems to have an effect within the new subfs system? Is there something else that I am missing here? I would think this would be a major problem, but I seem to see very little (nothing) posted about slow usb drives, so I kind of figure I am doing something wrong here, but I can't figure out what it is.
Thanks for any help,
Chuck
Not that anyone is paying attention, but I have some additional information to add. It appears that the slowness has nothing to do with subfs. I removed subfs and mounted the drive by hand, and it was still slow. I think I have determined that this is because it is only recognizing my usb drive as usb 1.1 (full speed) and not usb 2.0 (high speed) even though it was correctly recognized in Suse 9.0 as high speed. This comes from comparing the following lines from the /proc/bus/usb/devices file in Suse 9.0 and the new infomration in /sys/bus/usb. The relevant lines in the /proc/bus/usb/devices file from Suse 9.0 read:
T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 3 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=0caf ProdID=2507 Rev= 0.01 S: Manufacturer=BUSlink S: Product=USB 2.0 Hard Drive S: SerialNumber=200306273075
from which I gather that Spd=480 means 480 Mbit/sec (usb 2.0) as it should. However, when I mount it on my newly installed suse 9.1 system, the /sys/bus/usb/devices/1-1/speed file contains just the number 12, from which I infer that the speed is 12 Mbit/sec (full speed), which is not correct for usb 2.0. I also get this line in /var/log/messages:
kernel: usb 1-1: new full speed USB device using address 2
Again, I beleive the "full speed" is indicating usb 1.1 and not usb 2.0.
Thus, it appears that the problem is with the USB system itself. I had heard rumors that the 2.6 series of kernels had problems implementing USB correctly. Could this be what's happening here or what? This is a real show stopper for me because I transfer large data files to and from USB drives on a regular basis, and I cannot afford this terrible performance drop.
Is this a known issue or should I consider submitting a bug report?
Chuck
Well, I may have answered my own question. I was trying to use the USB 2.0 drive on my Dell Precision M50 laptop, which was a spare I was testing 9.1 on before installing it on my primary laptop, which is a Compaq Evo n800c. I have suse 9.0 installed on the Compaq and 9.1 installed on the Dell. After looking at the Dell specs again, I noticed that the two USB ports on there are only USB 1.1, whereas the Compaq has true USB 2.0 ports. Thus, this issue was hardware and not software related. I didn't realize that the Dell was so old that it didn't support USB 2.0. Sorry for the extraneous posts, but at least it helped me clear my head and isolate the problem. Chuck -- Dr. Charles H. Panzarella Senior Scientist, Ohio Aerospace Institute NASA Glenn Research Center Cleveland, Ohio, USA