External drives · Upgrading, transferring and backing up the drive
Can I use Transfer Drive to move to a smaller external drive?
Short answer: Only if it has room for everything Storage Studio keeps on your current drive — Transfer Drive checks free space first and won't start on a drive that's too small. Move back or remove items first to shrink what needs copying.
Only if it has room for everything Storage Studio keeps on your current drive. Transfer Drive checks the free space on the new drive before copying, and a drive that's too small can't be started at all.
If you want to downsize, first move back to your Mac (or remove) things you no longer need on the fast drive so there's less to copy — then run Transfer Drive again and it will recheck.