Ok. Now the defrag will move all files, even the ones who are not necessarsy to move. With to litte free space to do it.
I suggest to shrink the node a bit, to reach 200gb free.
Vadim and i running 20tb drives. With primocache wich reduces defragmentation before writing to the drive.
However its not a free program and requires an other ssd/ram and an additional ups if writecaching is enabled, no matter if ram or ssd cache.
There is even an diskrepancy from the disk size because 1000 or 1024 bit conversion.
Wich is a manufacturer thing.
There is filesystem space after formating. They are ~ 18.7 tb after 10% i set the node to max. 16.3 tb.
There are never 20 tb to use on a 20 tb drive.
My 12 tb node disk is set to 10 tb node data.
There are reasons for this 10% recommendation.
How much ram has the node and how much is the mft size ?
If the mft size is bigger than ram, it will swap alot on the swap partition. Thus stopping a defrag takes a while.
I recommend normal defrag and mft defrag, not sure in wich order. Or if the order matters.
Also the databases should be already on ssd./ second drive/ ntfs 4k formated reliable usb flashdrive temporarily.