Comment 2 for bug 2021999

I don't know if the customer reached out to Dell team and provided logs for investigation previously.
As far as I can tell, the analysis in the above 'Bug Description' is not accurate.

For example,

Issue 1:
It's said 'because of exists initiator group(which was created from previous runs and not cleaned up). '
Actually, the driver doesn't cleanup initiator group, but reuse the existing one when it matches.

Issue 2:
The lock "/var/lib/cinder/cinder-emc-sg-OS-no_SLO-SG-000197602020” is a lock of the default storage group. since the default storage group is not inside a parent SG and not inside a masking view, it should not be acquired by below code:

https://github.com/openstack/cinder/blob/stable/yoga/cinder/volume/drivers/dell_emc/powermax/masking.py#L1360-L1363

            @coordination.synchronized("emc-mv-{parent_name}-{serial_number}")
            @coordination.synchronized("emc-mv-{mv_name}-{serial_number}")
            @coordination.synchronized("emc-sg-{sg_name}-{serial_number}")
            def do_remove_volume_from_sg(
                    mv_name, sg_name, parent_name, serial_number):