I have a running VIO server that was managed via IVM. We made the (apparent) mistake of trying to connect a HMC server to it. Other than making a connection, no work has been done via HMC. We've since decided we don't want to use HMC and it's been powered off for a couple of weeks. However, being that the VIO server knows of the HMC, we receive the notice "[VIOSE01010003-0245] Unable to perform operation because this partition does not have sufficient management authority.".
How can we remove HMC's tentacles from the VIO server?
In case the 01 in the server's display (left bottom corner) changed to HMC you'd have to do a factory reset through the ASMI. However, I am unsure whether removing all service processor settings (that includes all partiton information) will result into an IVM (which basically is the first partition on such a system) after booting the IVM. So make sure that you have backup(s) of both the IVM installation (backupios) and the LPAR (mksysb). It would be great if you share the experience whether resetting the SP and booting the IVM suffices.
ASMI can be used by commandline IBM Systems Information Center or by GUI YouTube - p5 factory reset