I messed up my Windows partition, so I made a backup of it to an external USB drive partition using `dd if=/dev/sdb1 of=/dev/sdg2 ...`. Later using `testdisk` with some great help from testdisk and the ntfs-3g folk I repaired them both. But now mounting the external drive through the KDE UI in Kubuntu 12.04 amd64 gives errors. Clicking to mount the drive in Device Notifier displays "Could not mount the following device"; clicking to mount the drive in Dolphin displays
An error occurred while accessing "WinCBackup', the system responded:
The requested operation has failed.: Error mounting: mount exited with
Exit code 1: helper failed with:
mount: according to mtab, /dev/sdb1 is already mounted on
/mnt/WindowsXPDrive
mount failed

Well, yes indeed /dev/sdb1 is already mounted. I'm trying to mount the external drive, note it has a different label. `sudo mount /dev/sdg2 /mnt/test` works fine.

I guessed at the problem, and `solid-hardware list details` and `blkid` seem to confirm it: the two drives have the same uuid, StorageVolume.uuid = '3cc499c2c4997eb8', and
/dev/sdb1: LABEL="Windows XP" UUID="3CC499C2C4997EB8" TYPE="ntfs"
/dev/sdg2: LABEL="WinCBackup" UUID="3CC499C2C4997EB8" TYPE="ntfs"
So Solid or udisks thinks it's already mounted. But that seems silly, these are two different devices with different labels, different parent devices, major/minor numbers, labels, etc.

1. Is this a bug? If so, is it in Solid or udev/udisks?
2. Assuming the workaround is to give the external drive partition a different StorageVolume.uuid , how do I go about doing that for an NTFS volume?

Thanks!

I would consider this a bug. Unfortunately I do not know how to change the UUID - However it does seem plausible that someone would want to mount copies of the same image multiple times. Please file a bug report at bugs.kde.org regarding this. Based on the error message I suspect the Solid developers may need to work with the UDisks developers to fix this.

Thanks for the response, I filed https://bugs.kde.org/show_bug.cgi?id=303508 in Solid:libsolid-udisks.

There's no tool to change the UUID of a NTFS partition. Google finds command sequences using `dd` to overwrite magic offsets in the raw partition.