My Linux server (Centos 7.5) is in a strange state with USB drives. When I try to mount a partition on a USB drive to a newly created mount point I get the error
mount: /dev/sdd1 is already mounted or /mnt/foo busy.
/mnt/foo
is a newly created mount point, so it should not be busy. Which implies that /dev/sdd1
is already mounted. However, when I try to unmount it I get the error
umount: /dev/sdd1: not mounted
The system appears to be in some confused state where I can neither mount or unmount a USB drive?
Is there some command I can run to get things right so that I can mount a USB drive? I don't want to have to reboot the system. The details are shown below. Thanks
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
...
sdd 8:48 1 29.8G 0 disk
└─sdd1 8:49 1 29.8G 0 part
# mkdir /mnt/foo
# mount /dev/sdd1 /mnt/foo
mount: /dev/sdd1 is already mounted or /mnt/foo busy
# umount /dev/sdd1
umount: /dev/sdd1: not mounted
UPDATE: the USB storage subsystem seems to be in a bad state. When the USB drive is removed, the 'lsusb' output still shows the device. And when other USB drives are inserted, they don't show up at all. I tried to unload and reload the 'usb-storage' kernel module, but because it is in use it won't unload it.
I think this could be a firmware or hardware issue.