Hi,
No that is definitely not normal behavior, especially for a relatively small collection (36GB isn't that large). I would highly recommend checking the dspace.log (log files) to see if you are receiving errors or warnings. If you are seeing no activity in the logs then the process has likely stopped completely and nothing is actively changing.
As a sidenote, it's also worth noting that there's no need to do an export (to AIPs) and reimport (from AIPs) when moving from 5.8 to 7.2. The easier way to do this upgrade is to simply follow the upgrade instructions:
https://wiki.lyrasis.org/display/DSDOC7x/Upgrading+DSpace If the 5.8 database is on a different machine, it's still possible to do this same sort of upgrade, but you'd need a few extra steps:
1. First, it may be easiest to install DSpace 7 without any data first (just to make sure everything works well). Once satisfied, stop Tomcat (backend)
2. Copy your entire database contents to your new database (e.g. for Postgres, use tools like pg_dump and pg_restore). This copies all metadata/relationships over to the new server
3. Copy over your entire [dspace]/assetstore folder (including all subdirectories) to the new location. This copies all files over to the new server.
4. Run "./dspace database migrate ignored" to upgrade your database/data up to 7.x compatibility
5. Start Tomcat (backend) & frontend
6. Finally, reindex all content into the search engine (Run "./dspace index-discovery -b")
It's really hard to give you better advice as it's unclear what could be going on based on what you've shared. But, this doesn't sound like normal behavior.
If you find anything else in the logs that are clues, let us know on this list.
Tim