Had a user getting random slowdowns. Event Viewer showed "Bad Blocks". Tried PC Mover, it failed to transfer. Made a Batch file like I used to use,
@echo off
cd \
XCOPY /E .\*.* >NULL
exit
It was taking a LONG time so I started using File Explorer and going Folder by Folder. Finally found culprit outlook .ost file.
At home tried following:
@echo off
echo %time% >log
xcopy /E C:\2017-V\*.* C:\CopyTest\
echo %time% >>log
:
echo Step 2
echo %time% >logN
xcopy /E C:\2017-V\*.* >NUL
echo %time% >>logN
:end
============RESULTS===============
C:\Users\James>more log
18:06:40.12
18:06:42.06 (2 seconds)
C:\Users\James>more logn
18:06:42.06 (after 6 minutes I hit CTRL-C)
C:\Users\James>more logn
18:06:42.06
18:12:20.96
C:\Users\James>
===========================
ABSOLUTELY UNACCEPTABLE as the NUL Driver is supposed to just take whatever it is given, replace it each time with the next block and keep saying, all is OK. It never actually moves anything anywhere except maybe to its buffer.
Writing to the NUL device should always be faster than any physical writes.
SO WHAT GIVES, Microsoft?