[Qemu-discuss] qemu-kvm - usb timeouts

[Boryeu Mao]

Dear List -

I am receiving warnings of usb timeouts (and resetting) for an USB
flash drive that is attached to qemu-kvm.  If this is not the proper
forum to ask for help, please excuse the post and point me in the
right direction.

The USB drive is attached to qemu-kvm for an OS installation (from the
iso file) as follows:
   qemu-kvm -cdrom Install-DVD.iso -m 1024 -usb -device
usb-host,hostbus=1,hostaddr=8 \
          -hda disk.img
The installation eventually is completed, and successfully so, as the
usb drive can boot the newly installed OS properly.  (The OS being a
testing release of Scientific Linux 7.)  However, the installation
time to the usb drive (Kingston DT101 8gb) is much longer than
expected in comparison to the installation to a virtual disk image
file (via -hda): a factor of 10 to 12 was observed.  The slow-down is
attributed (I believe) to the continual usb timeouts and resets during
installation, indicated by the numerous warning messages that are
emitted when the reset takes 1 second or longer.

So perhaps there may be some parameters that needs to be specified
porperly to qemu-kvm, or the usb interface requires adjustment.  The
qemu-kvm is run under Scientfic Linux 6.5 (RHEL 6.5 - kernel
2.6.32-431.20.3.el6.x86_64) on an HP Pavilion g6 laptop.  Any help or
pointers will be greately appreciated.

Thanks in advance -
Boryeu Mao