Question:
How Much Free Space Is Needed On The Source Partition For The "Rearrange an account" Functionality To Work?
Answer:
Here, "Source" refers to the home directory of the cPanel account that is about to be rearranged/moved and "Target" refers to the mount point for the destination partition where that cPanel account is going to be moved to.
When using the "Rearrange an account" functionality, you can use the following Perl subroutine to get the exact free space needed on the target partition (here "/home2") in order to be able to move a specific source account (here "/home/cptest/"):
/usr/local/cpanel/3rdparty/bin/perl -MCpanel::DiskCheck -E 'say Cpanel::DiskCheck::target_has_enough_free_space_to_fit_source( "target" => "/home2", "source" => "/home/cptest/");'