USB card Reader Won't Unmount

[mrkeef]

Hi,

I have a USB card reader that I use to swap files between my desktop PC and a laptop- it's a Kodak 6-in-1 card reader and I use a CF 64 MB card.

For some reason when I try to unmount the card it always says "device is busy". If I try to force the unmount it tells me only root can do that, and as root I get device is busy.

I have the following in my /etc/fstab:

/dev/sda1 /mnt/card auto noauto,rw,users 0 0

Also after mounting and unmounting the device I have the following processes which remain even after killing them

1682 ? 00:00:00 usb-storage-0
1683 ? 00:00:00 scsi_eh_0


I wouldn't mind except that files are not always being written to the card when i expect them to be.

Can someone tell me what I've done wrong?

Thanks

[SkyNet]

You need to make sure you are not in the directory you are trying to umount, and also any program that is using the drive or has used the drive will need to be shutdown. The later is only a sometimes issue.

One last thing. This thread might help you a little bit maybe.
http://www.getlinuxonline.com/yabbse...p/topic,2194.0

[mrkeef]

Thanks for the reply SkyNet.

As far as I can tell no other programs are using the card at the time. But that link you've posted might help. I've got "noauto" in the fstab entry, but it looks like I need to change that to "auto".

Keith

[vwgtiturbo]

I had this problem with an external USB hard drive for a while and with thumbdrives, but found something that kind of works...
Instead of forcing the umount, use "umount -l /mount/point". In the man page for umount:
-l = Lazy unmount. Detach the filesystem from the filesystem hier*archy now, and cleanup all references to the filesystem as soon as it is not busy anymore. (Requires kernel 2.4.11 or later.)
This worked for me, as I can use 'df -h' and the external drive will no longer show as mounted. I don't know if this will help or not...

[mrkeef]

What I've been doing is using sync to ensure the files are actually written to the card. i think lazy unmount will unmount but it won't necessarily ensure that the contents of the device match what's in the filesystem.

A week or so ago, it suddenly decided to be read only and had to do mkfs (aka "format") on it to reset it.

Anyways I think I've got a handle on this for now... at least until it starts misbehaving again!

Keith