how to add USB drive to Update manager

[Tapas Mishra]

I want to upgrade 11.04 to 11.10 I have downloaded alternate ISO on a USB.
In update manager GUI---> Add volume while USB is inserted and I click
add volume I get
Please insert a disk in drive.
Why is there a default assumption that some one will Upgrade from a CDROM only.
Can't it be a USB (in my case) and then I get an error
Error scanning the CD
E:Unable to stat the mount point /media/cdrom/ -stat( 2: No such file
or directory), E:Unable to stat the mount point /media/cdrom -stat (2:
 No such file or directory),
E: failed to mount the CDROM.

and then I can not proceed.
I have alternate ISO of 11.10 on a USB stick and want to upgrade from
the USB is it possible?


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Tapas