Why does "move directories" on a NAS take so long?

Question

I am quite unsure of how the move files/directories use case in a client and NAS scenario technically works - perhaps someone can enlighten me or tell me if this is normal OS-behavior.

I have a NAS ( Synology DiskStation ) in a Gigabit-LAN with sometimes big directories ( in the range of ~ 10GB ) which I want to move somewhere else on the same NAS ( even on the same hard disk ).

The problem is that if I move a directory from lets say

//diskstation:/dir_foo/dir_1/src_1

to

//diskstation:/dir_foo/dir_2/

via my Windows 7 Desktop PC in Explorer ( I even tried it in Finder on MacBook ) this can take up to 10 Minutes (or the like) and I really wonder why this is the case. To me this seems as if the whole data was first transported over LAN to my client PC and then afterwards moved back to the NAS!?

Shouldn't the explorer or the NAS notice that this is local file operation so that the data doesn't have to be transported through my LAN and the movie should be much quicker? How can I analyze if the file movement is really executed over LAN? Because if i wanted to do these kind of operations via VPN from external, it would be pretty much unusable... Is this normal behavior?

Answer 1

If you are using your windows explorer for moving the files then your OS will first download the file from source directory to client PC and then upload it to target directory, this is because your using SAMBA shares.

If you want to move files quickly within your nas then best way would be to use putty or WinSCP which uses ssh & ftp etc.

Answer 2

It's hard to give a firm answer, because it depends. What access protocol are you using, and what operation are you performing? Is it a drag-drop in your GUI?

Your NAS does what it's told. It almost certainly implements some sort of internal rename function, that means you don't need to copy data in order to 'move' it.

If you do this from the command line, using 'move' or 'mv' (depending on DOS/Unix) do you have the same problem? I'm prepare to bet you don't, because you're telling the NAS to rename, and it will, and it'll be fine.

Answer 3

Move it from the GUI instead of the file explorer.