I have a root directory 'data_0'. Under this directory are about 15,000 directories ('a', 'b', 'c', ... 'aa', 'ab' ...). Under each of theses directories there are thousands of very small files (4~10kB), something between 1,000 and 2,000 files each.
All this leads to 30 million files. I need to move these from 'data_0' to a 'data_1' folder, but without the "level 2" folders (a, b, c etc), so:
/data_0/a/1.txt --> /data_1/a_1.txt /data_0/a/2.txt --> /data_1/a_2.txt ... /data_0/ccc/989.txt --> /data_1/ccc_989.txt ...
How far can I go with this? Performance is unimportant here. Is there a logical limit or just a performance limit?