I’m trying to do rclone sync remote1: remote2: to sync all the files on remote1 to a newly registered remote. But rclone then starts downloading all files to my local hard drive, quickly filling it up. remote1 is >10TB and crypted, which is quite a lot more than I have available locally. How can I make rclone sync a limited amount of files (and then delete them from my local drive) before syncing a new batch?
Can you copy and paste the exact command you are trying? As far as I know it shouldn’t be writing anything to disk. I was under the impression everything is done in RAM.
It does it in memory. I suspect that remote2: in your example is a “local” remote if you are having issues with it filling your drive.
I must have done something wrong, not sure what - but now it’s working as expected. Tried multiple times to rclone google-encrypted: google2-encrypted: but must have missed something as it created a ~/google2-encrypted folder and started storing everything there. Either way must have been my bad - thanks for confirming so I tried once more and got it working 
In that case you likely missed the trailing :