I had the same problem. I changed SecSt address according to
instructions. I noticed that SecSt has old ip address in properties
under Infrastructure->SecondaryStorage and CloudStack uses old IP to
mount SecSt and snapshots ar failing.
I found out that CloudStack DB has table cloud.image_store which
contains SecSt URL too.
Look at she table with SELECT * FROM cloud.image_store;
You have to update URL parameter in this table also.
It is not documented , but it seems it worked for me.
I suppose it is documentation bug, but man, this was pain...
