Arch Linux

Dyno

Member

Registered: 2013-11-20

Posts: 3

[Solved] Slow copy to usb

Hi!!.

I have a problem when copying files to a flash drive. The copy is very slow. A 1.7 GB file takes 22 minutes.

I followed the instructions on the Wiki https://wiki.archlinux.org/index.php/US … B_pendrive but did not work.

I have two hard drives, an SSD and a mechanic.

I discovered that if I add "elevator = deadline" in the grub, 1.7 Gb file copy takes 6 minutes.

But with "elevator = deadline" the rtorrent malfunctions. I have to write "elevator = noop" in the grup to run well the rtorrent.

Can automatically mount only pendrives as "elevator = deadline"?

Sorry for my English. Thank you very much.

Last edited by Dyno (2013-11-21 18:02:57)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,690

Re: [Solved] Slow copy to usb

I know you said that it takes 6 minutes with  "elevator = deadline".   Disregarding that for a moment,  1.7GB/22 minutes is very close to 10Mbits/second.  That is (coincidentally) almost exactly the transfer rate one might achieve with a full speed USB device.   Is there any chance that the device is connecting as a full speed device (12Mbits/sec) rather than as a high speed device (480Mbits/Sec)?

Any chance that when using  "elevator = deadline" that it is attaching as a high speed device; but as a full speed device otherwise.  1.7GB/6Min is 38Mbits/sec.

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johni

Member

Registered: 2012-02-03

Posts: 102

Re: [Solved] Slow copy to usb

If you want to set just your USB drive to use the deadline scheduler, you can do it like this:

If you flash drive is /dev/sdc, then:

echo "deadline" >/sys/block/sdc/queue/scheduler

Dyno

Member

Registered: 2013-11-20

Posts: 3

Re: [Solved] Slow copy to usb

Thaks.

I know you said that it takes 6 minutes with  "elevator = deadline".   Disregarding that for a moment,  1.7GB/22 minutes is very close to 10Mbits/second.  That is (coincidentally) almost exactly the transfer rate one might achieve with a full speed USB device.   Is there any chance that the device is connecting as a full speed device (12Mbits/sec) rather than as a high speed device (480Mbits/Sec)?

Any chance that when using  "elevator = deadline" that it is attaching as a high speed device; but as a full speed device otherwise.  1.7GB/6Min is 38Mbits/sec.

The tests are made on the same USB, high speed (2.0).

If you want to set just your USB drive to use the deadline scheduler, you can do it like this:

If you flash drive is /dev/sdc, then:

echo "deadline" >/sys/block/sdc/queue/scheduler

I knew that, but wanted to know if the flash drive can be mounted automatically.

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: [Solved] Slow copy to usb

You can probably write an udev rule to change the scheduler for removable devices, or just that particular device.

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Dyno

Member

Registered: 2013-11-20

Posts: 3

Re: [Solved] Slow copy to usb

rTorrent failed again today . Scheduler is not to blame for the failure.

At least I will fix the problem with the flash drive. "elevator = deadline" in the grub.

I have to find the problem for the rtorrent.

Thank you all.