New drive, lots of space, but fragmented

[Kwong]

I just installed a new drive. I used windows to copy the contents of a back up drive to the new drive. There is lots of free space on the new drive. However, a status report shows the new drive is fragmented? Why? New drive is NAS2 in this photo: http://www.ycreek.com/bob/temp/fn1.PNG

Thanks,
bob

 

[cyberjock]

Because that's how ZFS decided to write the data. Nothing special to see, and that number doesn't mean quite what you think it means. It's a prerequisite to a more optimized writing system that is yet to be designed. :P

 

[Kwong]

Thank you cyberjock. So I guess it is not due to using windows copy via CIFS - as opposed to rsync inside the NAS box.

 

[cyberjock]

Thank you cyberjock. So I guess it is not due to using windows copy via CIFS - as opposed to rsync inside the NAS box.

Nope. It's sheer chance and how ZFS decides to write the data.

Keep in mind that while you and I would consider 20%+ fragmentation on windows to be devastating for performance, it's really not a big deal for ZFS. I'm pretty sure that 20% fragmentation on Windows does not translate to 20% on ZFS.