Total Commander

I often copy large folders from one SD card to another. Often these folders are much larger than available space on the phone's internal storage. Right now I have to manually keep track of where I am in the source folder and how much space is available for swap on the phone while also juggling the SD cards, and the storage settings app for 'eject'.

I remember back in the early 90s there was a utility called copy2plus which kept track for me when copying large files between floppies using internal memory for swap -- it would just prompt me to remove the disk, insert disk 2, now reinsert disk 1, etc... I'd really like to see something like that in TC/Android, where it would keep track of what has been copied, how much internal storage is available, and prompt me to eject a SD card and mount the other SD card.

Thank you.

Your context is not very clear. I assume you have one SD card at the same time in your mobile.
I insert one SD card -with an adaptor - in the card reader of my PC. Then I copy the files. Switching SD cards in a running mobile is not a good idea. So I switch off the mobile, remove the case and change the cards. Then I restart the mobile. And be carefull when applications on the mobile use the SD card as storage.

i use sd cards for mass storage. all of the devices we have access to are running Android 5, are not rooted, and have only 1 internal sd slot and getting adapters or dongles is impossible. i know its not ideal, but it is pretty much the only option available to me. when swapping sd cards. i dismount then eject, or power down then eject. (some of the tablets we have access to do not gave the dismount button in the storage settings)

anyway it is always a big hassle copying between 2 large 512gb sd cards with limited internal storage. of 16gb. that's what made me think of copy2plus on the old Apple ][, copying data between floppies using limited internal memory.