I have a mongodb 1.8.2 with replica set. ( 1 Primary and 2 Secondary). I would like to upgrade to latest stable version i.e 4.4. Is there any way to do it? As the oldest version available is 2.6? Can I export and import data or take backup of 1.8.2 and restore in 4.4 ?
I addressed this question more generally in your related discussion topic which mentions MongoDB 3.2 as a starting point: Replace mongodb binaries all at once? - #3 by Stennie_X.
Upgrading via mongodump and mongorestore should be possible, however the MongoDB 1.8 release series is from 2011 and I’m not aware of anyone attempting to fast forward almost 10 years in a single upgrade.
I would try using a newer version of mongodump (perhaps 2.4 or 2.6), as 1.8-era mongodump didn’t support dumping the indexes and collection options (which newer versions save in collection.metadata.json files).
The latest version of mongodump is only tested with non-EOL server releases (currently MongoDB 3.6+) and I expect may rely on MongoDB 3.0+ storage engine API commands. I suggested 2.4 or 2.6 mongodump as there were some important bug fixes, but it has been a long while since I’ve worked with server or tool versions of that era.
Regards,
Stennie