Mounting a USB device fails with "Input/output error, mount: /dev/sdb already mounted or /mnt/ busy"

Issue

• We need to attach a USB disk to the machine, the system says that The device is already mounted. The machine is attached to a san and the multipath is handled by multipathd.

• This is the error:

[root@localhost ~]# mount /dev/sdjq1 /mnt/usb/
/dev/sdjq1: Input/output error
mount: /dev/sdjq1 already mounted or /mnt/usb/ busy