Hey Frediano, Thanks for responding - so I take it this is a server-side setting (how many channels are attached to the VM)? Also, is there a spice-gtk API that may be used to obtain the number of available USB channels at any given time? I.e. the UI of any client application should have a way to inform the user how many "ports" are still available at any point, right? Thanks! iordan On Fri, Dec 24, 2021 at 4:05 AM Frediano Ziglio <freddy77@xxxxxxxxx> wrote: > > Il giorno gio 23 dic 2021 alle ore 23:38 i iordanov <iiordanov@xxxxxxxxx> ha scritto: >> >> Hi guys, >> >> During my testing I've been unable to connect more than 2 USB devices >> at a time - could you please help me figure out why that's happening? >> >> The backend starts returning error with message "No free USB channel", >> but I can't see how to tune the number of USB channels available! >> >> 2021-12-23 15:27:52.608 29721-29760/com.iiordanov.aSPICE >> D/android-service: connect_cb: start >> 2021-12-23 15:27:52.608 29721-29760/com.iiordanov.aSPICE >> I/android-service: connect_cb: successfully redirected device >> 2021-12-23 15:28:00.499 29721-29760/com.iiordanov.aSPICE >> D/android-service: connect_cb: start >> 2021-12-23 15:28:00.499 29721-29760/com.iiordanov.aSPICE >> I/android-service: connect_cb: successfully redirected device >> 2021-12-23 15:28:03.582 29721-29760/com.iiordanov.aSPICE >> D/android-service: connect_cb: start >> 2021-12-23 15:28:03.582 29721-29760/com.iiordanov.aSPICE >> E/android-service: connect_cb: failed to redirect device, error: No >> free USB channel >> 2021-12-23 15:28:06.385 29721-29760/com.iiordanov.aSPICE >> D/android-service: connect_cb: start >> 2021-12-23 15:28:06.385 29721-29760/com.iiordanov.aSPICE >> E/android-service: connect_cb: failed to redirect device, error: No >> free USB channel >> 2021-12-23 15:28:08.634 29721-29760/com.iiordanov.aSPICE >> D/android-service: connect_cb: start >> 2021-12-23 15:28:08.634 29721-29760/com.iiordanov.aSPICE >> E/android-service: connect_cb: failed to redirect device, error: No >> free USB channel >> >> Your help is very appreciated. >> >> Thanks! >> iordan >> > > Hi, > this is expected. Every USB channel allow to attach one USB device. Is like having 2 physical USB ports on your computer. If you don't use an HUB you can attach only 2 USB physical devices. Currently there's no software USB hub so one USB device takes one USB channel and by default only 2 USB channels are attached to the VM. > > Frediano -- The conscious mind has only one thread of execution.