unmanage pp device under W2K3

The command powermt unmanage is only supported on Unix platforms. For windows hosts you can run powermt remove for the particular devices that you do not want PP to control:

From the product guide:
powermt remove: Remove paths from PowerPath management
Platforms This command is supported on all PowerPath platforms.
Storage systems This command is supported on all storage systems.
Description powermt remove deletes the specified path (or paths) from
PowerPath's list of configured paths. It does not delete the logical
device that the paths refer to. As long as the logical device remains
visible on the system, the logical device can be reconfigured via
powermt config.
! CAUTION
Do not remove the last path to a logical device unless you plan to
remove the logical device entirely, as data access will be
interrupted.
On all platforms, powermt remove does not remove a path if that
native path is open¿for example, if a file system is mounted on the
native path device or an application has opened the native path
device. Instead, powermt remove removes all specified paths that are
not currently open, issues an error message, and exits.
If a PowerPath device is open, powermt remove does not remove that
device or the last path to that device.
In addition, powermt remove operates on paths, so when powermt
remove is executed with an HBA or PowerPath device argument,
powermt remove iterates through all the associated paths and
attempts to remove them. The HBA or PowerPath device is removed
only if all the associated paths are successfully removed.
To permanently remove a path from the PowerPath configuration:
1. Run powermt check or powermt remove.
2. Physically remove the path.
3. Remove the operating system objects associated with the path
and/or device.
4. Run powermt save.

I tried that before but device re-appears after a rescan of disk devices:

remove lun from storage group


Device(s) not found.


recan device under disk manager and powerpath device is back again:


Pseudo name=harddisk1
....
---------------- Host --------------- - Stor - -- I/O Path - -- Stats ---
### HW Path I/O Paths Interf. Mode State Q-IOs Errors
==============================================================================
2 port2\path0\tgt0\lun0 c2t0d0 SP A4 active alive 0 0
3 port3\path0\tgt0\lun0 c3t0d0 SP B4 active alive 0 0

i have not seen that command used much at all. from reading it , would seem in windows it is only a way to remove paths that are no longer valid . As long as you have devices and paths to those devices powerpath will report them and manage them in windows.

So it's a kind of all or nothing under windows for powerpath devices, no way to disable an individual device or HBA.

are they not getting removed because they are online/active?

yes, without removing them from the storage group I can't remove them from powerpath.

that would just be the nature of windows I/O stack

Why are you trying to remove devices from PowerPath that are assigned to the host?

If you have devices masked to the host from an EMC array, and there are multiple physical and/or logical paths to the devices on the array then you should be using PowerPath to manage those devices.