How long should I expect to wait to import a 500Mb zip from a previous Bamboo instance 5.12 to a new 6.4 instance? After 7 days it's still busy. What is it doing and why is it doing it so slowly?
7 days is excessive - did you take a look at the <BambooHome>/atlassian-bamboo.log to see what it is doing? It could be that the process actually failed but the UI doesn't reflect that. What we commonly see during imports is that the default heap size of Bamboo isn't sufficient that you therefore run out of heap (or garbage collection limits are reached), causing the process to fail.
If you're seeing evidence of the latter, you can follow the information in https://confluence.atlassian.com/bamkb/outofmemory-errors-in-bamboo-82870484.html to adjust your heap size.
Premier Support Engineer