Seafile migration

Hi Lads,
I need some guidance.

I have two seafile servers now… One is old ubuntu 16.10 with seafile 7 CE Server.

Recently purchased seafile Pro edition and new no data on ubuntu server 22.10 minimal. Seafile latest version 11 i think

Lets call Old server as OLD7 and NEw as NEW11.

I want to move all data to new server. but when i retrive data from dummy machine on windows using seafile client takes long time, plus some gets stuck on indexing error. and i am losing time. Data is about 1.5TB. i have an external drive as well.

Any way outside box ideas to get that data and dumb on new server under one account still fine. i can manually create user accounts on new server. not a problem. but for me data is important in such way its there in external drive and i put them back on new seafile.

Please assist. can i run seafile client on OLD7 itself accessing 127.0.0.1 and transferring data to external? or any other suggestion so far it seems using 127.0.0.1 and putting data on external via client sync seems best option.

Please advice