The following procedure may help find a device identifier or device file for a newly added hardware device in GNU/Linux . In the example I am connecting a USB pendrive

You can find the details from the Linux kernel log

hnlinux:~ # tail -f /var/log/messages

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May 2 01:38:24 hnlinux kernel: usb 1-7: new high speed USB device using ehci_hcd and address 8
May 2 01:38:24 hnlinux kernel: usb 1-7: new device found, idVendor=0781, idProduct=5151
May 2 01:38:24 hnlinux kernel: usb 1-7: new device strings: Mfr=1, Product=2, SerialNumber=3
May 2 01:38:24 hnlinux kernel: usb 1-7: Product: Cruzer Micro
May 2 01:38:24 hnlinux kernel: usb 1-7: Manufacturer: SanDisk Corporation
May 2 01:38:24 hnlinux kernel: usb 1-7: SerialNumber: 20052845221D9DB1625F
May 2 01:38:24 hnlinux kernel: usb 1-7: configuration #1 chosen from 1 choice
May 2 01:38:24 hnlinux kernel: scsi7 : SCSI emulation for USB Mass Storage devices
May 2 01:38:24 hnlinux kernel: usb-storage: device found at 8
May 2 01:38:24 hnlinux kernel: usb-storage: waiting for device to settle before scanning
May 2 01:38:29 hnlinux kernel: Vendor: SanDisk Model: Cruzer Micro Rev: 0.1
May 2 01:38:29 hnlinux kernel: Type: Direct-Access ANSI SCSI revision: 02
May 2 01:38:29 hnlinux kernel: SCSI device sdb: 8027712 512-byte hdwr sectors (4110 MB)
May 2 01:38:29 hnlinux kernel: sdb: Write Protect is off
May 2 01:38:29 hnlinux kernel: sdb: Mode Sense: 03 00 00 00
May 2 01:38:29 hnlinux kernel: sdb: assuming drive cache: write through
May 2 01:38:29 hnlinux kernel: SCSI device sdb: 8027712 512-byte hdwr sectors (4110 MB)
May 2 01:38:29 hnlinux kernel: sdb: Write Protect is off
May 2 01:38:29 hnlinux kernel: sdb: Mode Sense: 03 00 00 00
May 2 01:38:29 hnlinux kernel: sdb: assuming drive cache: write through
May 2 01:38:29 hnlinux kernel: sdb: sdb1
May 2 01:38:29 hnlinux kernel: sd 7:0:0:0: Attached scsi removable disk sdb
May 2 01:38:29 hnlinux kernel: sd 7:0:0:0: Attached scsi generic sg1 type 0
May 2 01:38:29 hnlinux kernel: usb-storage: device scan complete
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You can see that the device file /dev/sdb has been assigned to the device.

You can mount the device from the above information with ease