The most general way - -
Use the kernel message buffer display and clear command:
sudo dmesg -c
Change something in the hardware set-up (as plug in a usb device).
Use the kernel message buffer display command:
core2quad ~ $ dmesg
[ 8946.736034] usb 2-1: new high speed USB device number 2 using ehci_hcd
[ 8947.127009] usbcore: registered new interface driver uas
[ 8947.128905] Initializing USB Mass Storage driver...
[ 8947.129068] scsi6 : usb-storage 2-1:1.0
[ 8947.129148] usbcore: registered new interface driver usb-storage
[ 8947.129150] USB Mass Storage support registered.
[ 8948.129247] scsi 6:0:0:0: Direct-Access Kindle Internal Storage 0100 PQ: 0 ANSI: 2
[ 8948.132576] sd 6:0:0:0: Attached scsi generic sg5 type 0
[ 8948.136710] sd 6:0:0:0: [sde] 2797568 512-byte logical blocks: (1.43 GB/1.33 GiB)
[ 8948.242018] sd 6:0:0:0: [sde] Write Protect is off
[ 8948.242021] sd 6:0:0:0: [sde] Mode Sense: 0f 00 00 00
[ 8948.351699] sd 6:0:0:0: [sde] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 8948.574350] sde: sde1
[ 8948.860206] sd 6:0:0:0: [sde] Attached SCSI removable disk
Which is the kernel reporting that a Kindle in "Storage device mode" has just been added to the system.
See the next to last line above?
That means the Kindle storage device is now known as /dev/sde1 (in this specific example - names are dynamic - yours might be different).