Hello,
this amount of different export results may point to a general problem in the Records Management module. Provided you select the same set of data to export, you should end up with almost identical exports. Differences of up to 2.5 GiB are just too extreme not to be an indicator of inconsistent exports. Unfortunately, I have not worked a lot with Records Management myself and have no experience with the export behaviour. I haven't found an issue for this in JIRA yet, but may just be using the wrong keywords.
You might try one of two things:
- test a migration to Alfresco 4.x with RM 2.x on a duplicate data set, and see, if the newer versions are able to produce consistent exports
- get a hold of Roy Wetherall (@rwetherall) or another RM dev (don't know the name of one at the moment though) via this forum, twitter or other social channel - maybe someone how knows more of the history of Alfresco RM (3.4 is history, I did not participate in - I've only dabbled in RM 2.x on Alfresco 4.x) can shed some light on this.
Regards
Axel