How do I force Robocopy to overwrite files?
<p>In general, Robocopy ignores files for which lastwrittendate and filesize are the same. How can we escape this design? I'd like to force overwriting with Robocopy.</p>

<p>I expected that dst\sample.txt should be written test001.
But these file are recognized as the same files by Robocopy and not overwritten. The "/IS" option is not effective in this case.</p>

<pre><code>New-Item src -itemType Directory
New-Item dst -itemType Directory
New-Item src\sample.txt -itemType File -Value "test001"
New-Item dst\sample.txt -itemType File -Value "test002"
Set-ItemProperty src\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"
Set-ItemProperty dst\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"

ROBOCOPY.exe src dst /COPYALL /MIR
Get-Content src\sample.txt, dst\sample.txt
&gt; test001
&gt; test002

ROBOCOPY.exe src dst /COPYALL /MIR /IS
Get-Content src\sample.txt, dst\sample.txt
&gt; test001
&gt; test002
</code></pre>