(I think, based on internet searches I know) that linux ext3 isn’t supposed to require defragmentation, however for reasons related to my synching of media files across numerous devices I have 60% non contagious files. (I think because large files are deleted and replaced with other large files).
I done a few inconclusive internet searches.
My question is … does OSMC include any disk utilities i could use to defrag or should I find something online, or leave my disk completely alone?
Unless you are seeing significantly degraded performance, my general advice is not to get too hung up on such figures.
The Linux System Administrator’s Guide has some useful advice (para. 5.10.11):
Modern Linux filesystem keep fragmentation at a minimum by keeping all blocks in a file close together, even if they can’t be stored in consecutive sectors. Some filesystems, like ext3, effectively allocate the free block that is nearest to other blocks in a file.
So, while being technically correct, the non-contiguous figure can give a misleading picture.
To answer your specific question:
(a) OSMC doesn’t include anything; and (b) subject to the caveat in the first paragraph, I’d suggest that you leave it alone