dmesg | tail
[ 7986.702811] usb 2-1: new full speed USB device using uhci_hcd and address 3
[ 7986.906681] usb 2-1: configuration #1 chosen from 1 choice
[ 8537.156771] FAT: bogus number of reserved sectors
[ 8537.156779] VFS: Can't find a valid FAT filesystem on dev sda4.
[ 8768.766523] usb 2-1: reset full speed USB device using uhci_hcd and address 3
[ 8844.278567] usb 2-1: reset full speed USB device using uhci_hcd and address 3
[ 8993.156991] usb 2-1: reset full speed USB device using uhci_hcd and address 3
[ 9077.229759] usb 2-1: reset full speed USB device using uhci_hcd and address 3
[10006.749046] FAT: bogus number of reserved sectors
[10006.749055] VFS: Can't find a valid FAT filesystem on dev sda4.