Lab 8.1

LexHoffman

Hi,

Following instructions for Lab 8.1 verbatim doesn't work for me.   At step 3 after connecting a usb drive and doing `ls -lF /dev | grep myusb` nothing is returned.

I've tried two different thumb-drives, a wireless modem dongle, and a webcam. 

Thanks in advance for any help.

Lex

luisviveropena

Hi Lex,

1) What distro and version are you using?

2) When connecting the usb device, please do 'dmesg' and attach the output of it.

Thanks,

Luis.

LexHoffman

Hi Luis,

I'm using CentOS 7, 3.10.0-514.2.2.el7.x86_64.

[62356.297197] usb 1-1.4: new high-speed USB device number 4 using ehci-pci
[62356.384331] usb 1-1.4: New USB device found, idVendor=0781, idProduct=5581
[62356.384336] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[62356.384339] usb 1-1.4: Product: SanDisk Ultra
[62356.384341] usb 1-1.4: Manufacturer: SanDisk
[62356.384343] usb 1-1.4: SerialNumber: A20037B0BA063325
[62356.409203] usb-storage 1-1.4:1.0: USB Mass Storage device detected
[62356.409693] scsi host10: usb-storage 1-1.4:1.0
[62356.409819] usbcore: registered new interface driver usb-storage
[62356.411807] usbcore: registered new interface driver uas
[62357.412088] scsi 10:0:0:0: Direct-Access     SanDisk  SanDisk Ultra    PMAP PQ: 0 ANSI: 6
[62357.412901] sd 10:0:0:0: Attached scsi generic sg8 type 0
[62357.413208] sd 10:0:0:0: [sdh] 30283008 512-byte logical blocks: (15.5 GB/14.4 GiB)
[62357.413902] sd 10:0:0:0: [sdh] Write Protect is off
[62357.413907] sd 10:0:0:0: [sdh] Mode Sense: 45 00 00 00
[62357.414671] sd 10:0:0:0: [sdh] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[62357.589459]  sdh: sdh1
[62357.592264] sd 10:0:0:0: [sdh] Attached SCSI removable disk

Cheers mate.

Lex

LexHoffman

This may also be useful:

➜  ~ udevadm monitor --subsystem-match=usb --property
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[62360.178801] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4 (usb)
ACTION=add
BUSNUM=001
DEVNAME=/dev/bus/usb/001/004
DEVNUM=004
DEVPATH=/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4
DEVTYPE=usb_device
MAJOR=189
MINOR=3
PRODUCT=781/5581/110
SEQNUM=3285
SUBSYSTEM=usb
TYPE=0/0/0

KERNEL[62360.179184] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4/1-1.4:1.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4/1-1.4:1.0
DEVTYPE=usb_interface
INTERFACE=8/6/80
MODALIAS=usb:v0781p5581d0110dc00dsc00dp00ic08isc06ip50in00
PRODUCT=781/5581/110
SEQNUM=3286
SUBSYSTEM=usb
TYPE=0/0/0

UDEV  [62360.196401] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4 (usb)
ACTION=add
BUSNUM=001
DEVLINKS=/dev/myusb
DEVNAME=/dev/bus/usb/001/004
DEVNUM=004
DEVPATH=/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4
DEVTYPE=usb_device
ID_BUS=usb
ID_MODEL=SanDisk_Ultra
ID_MODEL_ENC=SanDisk\x20Ultra
ID_MODEL_FROM_DATABASE=Ultra
ID_MODEL_ID=5581
ID_REVISION=0110
ID_SERIAL=SanDisk_SanDisk_Ultra_A20037B0BA063325
ID_SERIAL_SHORT=A20037B0BA063325
ID_USB_INTERFACES=:080650:
ID_VENDOR=SanDisk
ID_VENDOR_ENC=SanDisk
ID_VENDOR_FROM_DATABASE=SanDisk Corp.
ID_VENDOR_ID=0781
MAJOR=189
MINOR=3
PRODUCT=781/5581/110
SEQNUM=3285
SUBSYSTEM=usb
TYPE=0/0/0
USEC_INITIALIZED=360181015

UDEV  [62360.205815] add      /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4/1-1.4:1.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.4/1-1.4:1.0
DEVTYPE=usb_interface
ID_MODEL_FROM_DATABASE=Ultra
ID_VENDOR_FROM_DATABASE=SanDisk Corp.
INTERFACE=8/6/80
MODALIAS=usb:v0781p5581d0110dc00dsc00dp00ic08isc06ip50in00
PRODUCT=781/5581/110
SEQNUM=3286
SUBSYSTEM=usb
TYPE=0/0/0
USEC_INITIALIZED=182882

 

luisviveropena

Hi Lex,

So, the usb device is recognized by the OS.

1) Did you create the udev rule?

2) Did you reload the udev rules by restarting the udev service or rebooting the system?

Regards,

Luis.

LexHoffman

Thanks Luis,

It was 2.  I hadn't restarted the udev service.  As I have rebooted since starting this thread it is now working (you can see in my posted above... I didn't notice lol).

For future reference, to reload udev rules without rebooting on CentOS 7:

 

udevadm control --reload-rules

Thanks again!

luisviveropena

That's great, Lex, I'm glad that you were able to solve it

Have a great 2017!

Luis.