> We are looking to move our Moodle installation to a new server.
Are they full machines? Are they physically in your organization's premises or at a hosting provider
? What are the operating systems, web servers, database servers, PHP versions?
> We are currently running 1.9.2+ with a HUGE database (4496.25 MB). The size is definintely causing some obstacles.
What sort of problems?
> I thought since we are moving to a new server, it would be a good time to make the jump to 2.4.
Too hasty for my taste. Your upgrade path is -> 1.9.latest -> 2.2.latest -> 2.4.latest. One step at a time, take a good break after each step. Make sure that every thing is OK, then only move forward.
> installed 2.4 on the new server, but the databases are too large in the old 1.9 to do full backups of.
A fresh installation is not an upgrade. Compare http://docs.moodle.org/en/Installing_Moodle
> The other option would be to migrate 1.9 over to the new server, and then try to do an upgrade to 2.2, then to 2.4.
You always need to run two Moodle instances, say original and copy. At the beginning both are identical, i.e. 1.9.2+. Then you upgrade the copy to 1.9.latest. Test thoroughly. If all OK do the identical upgrade to the original.
Then repeat the same exercise for 2.2, then 2.4, ...
> But know that moodle tends to not always upgrade nicely (to put it mildly).
I heard that some where.