So here is my problem.
I have a site collection. In this site I have a list [ListA] that has lots of columns and lots of attachments and lots of items and over the threshold. I would like to create a copy of this list and place it on the same site collection. So basically duplicate ListA with a ListB. However the export and import functions do not give me the ability I need. I can export but the import function does not allow me to create a new list out of it. If I understand correctly it will overwrite the already existing listA. Is there a way to duplicate a list on the same site collection?
As I write this I thought maybe I could write a workflow that could copy data from ListA to an empty ListB but I don't know how easy that will be.
The list is over its threshold and affecting some outlook client calendar views. I would prefer to just archive and start a new list but that would bring downtime and the archived list would have to still be in use for a while. Many people use it and my client is afraid of all the users getting confused with 2 active lists. So my client wants no down time. So my thinking is to just duplicate ListA to ListB and delete old data from ListA and delete new data from ListB, thereby avoiding downtime.
Any ideas? Some one suggested I export to excel and recopy but this list has tons of attachments so it would not work.
EDIT Saving the list as a template with data will not work because SharePoint limits the content data to 10MB. This list is FAR beyond that. I could save the empty template true ... but I would still be stuck in finding an easy way [outside onetime custom code] to copy data across ...