I’ve been moving some large files between my mac and to my Pi’s external HDD and keep coming up against the fat32 file size limit of 4GB which is rather infuriating. I can’t change my disk format type, so I needed to get around it.

After having a look about I’ve found split and cat, meaning I can use command line tools to split the file into two and then join them again using cat. Unfortunately split wasn’t installed on my mac but does come with Raspian, so had to do that too.

Firstly to install split on my mac, in terminal:

brew install truncate

Now to split the file to be less than 4gb:

split -b 4294967295 /Users/Puk/Documents/filename.ext /Users/Puk/Documents/filename.ext

This command will split the file into filename.extaa and filename.extab, the first being 4.29GB the second being what’s left.

Move the files in anyway you wish to their destination, now it’s time to rejoin them which is very easy using cat. So in my case via ssh I use:

cat filename.extaa > filename.ext

Job done, the file is rejoined and you have a file larger than 4GB on your FAT32 disk!