# USB Modem ZTE MF100 Device is busy

## Aleksandr

Recently stopped working modem.

 In what may be the problem?

```
[  309.271636] USB Serial support registered for GSM modem (1-port)

[  309.271761] option 2-1:1.0: usb_probe_interface

[  309.271773] option 2-1:1.0: usb_probe_interface - got id

[  309.271795] option 2-1:1.0: GSM modem (1-port) converter detected

[  309.272150] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0

[  309.272173] option 2-1:1.1: usb_probe_interface

[  309.272186] option 2-1:1.1: usb_probe_interface - got id

[  309.272206] option 2-1:1.1: GSM modem (1-port) converter detected

[  309.272309] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB1

[  309.272329] option 2-1:1.2: usb_probe_interface

[  309.272339] option 2-1:1.2: usb_probe_interface - got id

[  309.272358] option 2-1:1.2: GSM modem (1-port) converter detected

[  309.272388] ehci_hcd 0000:00:13.2: reused qh ffff88012f0c6280 schedule

[  309.272397] usb 2-1: link qh2-0001/ffff88012f0c6280 start 1 [2/0 us]

[  309.273800] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB2

[  309.275184] usbcore: registered new interface driver option

[  309.275186] option: v0.7.2:USB Driver for GSM modems

```

```
zero@ZerO ~ $ ls -l /dev/ttyUSB2

crw-rw---- 1 root uucp 188, 2 Окт  7 08:53 /dev/ttyUSB2

zero@ZerO ~/Documents $ groups 

wheel uucp audio cdrom video games usb plugdev vboxusers zero

zero@ZerO ~/Documents $ wvdial

--> WvDial: Internet dialer version 1.61

--> Cannot open /dev/ttyUSB2: Device or resource busy

--> Cannot open /dev/ttyUSB2: Device or resource busy

--> Cannot open /dev/ttyUSB2: Device or resource busy
```

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## chithanh

Check with fuser or lsof if some other process uses the ttyUSB2 device.

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