Comment 4 for bug 1704071

There has been some disagreement here on how to best handle this with this temporary patch. I have submitted my new revision of the commit here that does swallow the exception in the case of VDI_NOT_IN_MAP which is what I believe Bob was mentioning when "looking for".

This commit looks for the VDI_NOT_IN_MAP within the exception, and then will verify that it is received from an XCP 2.1.0+ instance before returning and failing to raise. I have included in the commit message why I have decided this route over skipping the assertion completely, but I will include it here as well for posterity.

1. --Block-migration can be called without regard for whether an iSCSI volume is attached, and we still want to ensure that VIF, CPU and other factors are checked, and not just skip all checks entirely.

 2. Currently the Assert only exists within the --block-migration code base but this needs to change. A future commit will remove this logic to ensure that the commit runs without this flag. Once that is done we want to be able to continue to use this Exception swallow logic rather than continuing to skip the assert for all XCP2.1.0+ even without volumes.

-Brooks Kaminski
irc: Spazmotic