Solved: decided to avoid the funkyness this would invoke and just bought another drive. all good now👍
About a year back, I moved my internal 8tb and 4tb HDDs from my main Windows machine to my old PC-turned-Linux-server. They hold a bunch of bulk data like Youtube channel archives and torrents that are open to download.
I would like to do an in-place ext4 conversion, if possible. Currently I’ve just started shuffling data off to an SSD and the plan was to slowly shrink the NTFS partitions and turn the new space into ext4, 500gb at a time (size of the intermediary SSD), but it is taking an unbearably long time. Shrinking the 4tb partition in gparted has been running for 13 hours, with an estimated 22 hours remaining! And I’ll have to do it 7 more times for the 4tb, and 16 times for the 8tb!!
Is there a better way to do this?
Found that also myself trying to do the same thing haha. I did the same process as OP, gparted took 2.5 hours in my 1TB HDD to create a new partition, then copying the data from old to new partition was painfully slow, so I went to copy it to another dive and into the new partition.
Afterwards I deleted the old partition and grew the new one, which took a bit more than 1.5 hours.
If I had the space I would have copied all the data out of the drive, formatted it and then copied back into. It would have been quicker.