Subject: USB drive input / output error
To: None <,>
From: Shadi Ammouri <>
List: netbsd-users
Date: 07/17/2007 09:24:04

I'm running NetBSD-current on an ARM based system.

I have a problem after disconnecting a USB drive while a write
operation is active.

I do the following:
- mount the USB drive. (mount /dev/sd0c /mnt/disk")
- run dd to write some file to the disk. (dd if=/dev/zero
- disconnect the disk while the write operation is in progress.

From that point, I cannot unmount the drive, or remount it.
I get the following error: "umount: /mnt/disk: Input/output error".

The USB drive is formatted with FFS.
The only way by which I can resolve this problem is by restarting the system.

How can I recover from this error without restarting the system.