Moving Files results in both read and write on target disk and parity?

[localh0rst]

Hi All,

 

I hope my question makes sense, but I can't get my head wrapped around it:

 

I am moving files with unbalance from one drive of the array to another:

 

 

disk3 -> disk2.

 

So far so good. However, this is the R/W activity of Unraid:

 

 

To my understanding, the only activity should be: READ from disk 3, WRITE from disk 2 and WRITE on the two parities. Did I miss something?

I recently removed a failed disk (disk 4, it was emulated by the parity), made a new Configuration, left the disk 4 empty (I read something about not to touch the order of the drives when double parity is present) and rebuild the parity from scratch, like it is described in the wiki. No parity errors.

 

Now, why is disk 2 having READ access? And should the parity not also have only WRITE activity? 

Is there still someting emulated? 

 

Thanks for you help,

localh0rst

 

 

 

[JorgeB]

5 minutes ago, localh0rst said:

And should the parity not also have only WRITE activity? 

Not with read/write/modify write mode, and it's the only one that works when transferring disk to disk.

[itimpi]

For reference there is a description of the default Unraid write mode here in the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page. The Unraid OS->Manual section in particular covers most features of the current Unraid release.

[localh0rst]

Thanks guys, appreciate your help!