Visualizing disk fragmentation

[ByteMan]

Is there a way / tool to visualize how data is laid out on disks in use, similar to how some Windows tools shows filesystem fragmentation (see picture for reference)?
Alternatively, are there other ways to assess the current level of fragmentation on a disk or pool?
It is understood that data fragmentation itself cannot be easily determined, so I guess I am looking for the fragmentation of free space (ideally in a 'visual' form).

 

[sretalla]

Alternatively, are there other ways to assess the current level of fragmentation on a disk or pool?

zpool list -v and look at the %FRAG column

Is there a way / tool to visualize how data is laid out on disks in use, similar to how some Windows tools shows filesystem fragmentation (see picture for reference)?

No. At least none I am aware of.

I am looking for the fragmentation of free space

That's what ZFS calculates as %FRAG, so you have it.

 

[EsTaF]

"zpool list -v" command shows nothing at all. Unless, of course, you take into account the number about the total fragmentation.

That is, to optimize the free space, I will have to blindly recopy all the files))))), even if there are very few fragmented files.