The migration feature is essentially a DELT export + element delete + DELT import. I did some quick testing and the alarm data does not seem to be exported. Trend data and information events are, see below.

I have an element with some trending + 4 alarms before migrating.
The alarm tree:

The trend graph:

Now I migrated the element to another DMA.

The alarms were gone, you can see by the timestamp and alarm ID that it’s actually a different alarm that was created on the destination DMA (ID 396 in this case).

The trend graph is still correct though.
A quick peek in the code seems to confirm this, alarms are not migrated.
Information events are though, you can see the ‘Deleted by’ information event from during the migration + the new alarm being created on element startup below.

Given all this, I think that migrate duration is mostly impacted by:
– amount of information events
– amount of trended data
– type of database you’re using

I’m not sure how the ‘Weight’ and ‘Change’ columns are determined.