How do I force Robocopy to overwrite files

Question

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   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   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

User · Answer

This is really weird  why nobody is mentioning the  IM switch    I ve been using it for a long time in backup jobs  But I tried googling just now and I couldn t land on a single web page that says anything about it even on MS website     Also found so many user posts complaining about the same issue   Anyway   to use Robocopy to overwrite EVERYTHING what ever size or time in source or distination you must include these three switches in your command   IS  IT  IM   IS    Include Same files   Includes same size files   IT    Include Tweaked files   Includes same files with different Attributes   IM    Include Modified files  Includes same files with different times    This is the exact command I use to transfer few TeraBytes of mostly 1GB  files  ISOs - Disk Images - 4K Videos   robocopy B  Source D  Destination  E  J  COPYALL  MT 1  DCOPY DATE  IS  IT  IM  X  V  NP  LOG A  ROBOCOPY LOG  I did a small test for you    and here is the result                 Total    Copied   Skipped  Mismatch    FAILED    Extras     Dirs        1028      1028         0         0         0       169    Files        8053      8053         0         0         0         1    Bytes   649 666 g 649 666 g         0         0         0   1 707 g    Times     2 46 53   0 41 43                       0 00 00   0 41 44      Speed             278653398 Bytes sec     Speed             15944 675 MegaBytes min     Ended   Friday  August 21  2020 7 34 33 AM  Dest  Disk  WD Gold 6TB  Compare the write speed with my result  Even with those  quot Extras quot   that s for reporting only because of the  quot  X quot  switch  As you can see nothing was Skipped and Total number and size of all files are equal to the Copied  Sometimes It will show small number of skipped files when I abuse it and cancel it multiple times during operation but even with that the values in the first 2 columns are always Equal  I also confirmed that once before by running a PowerShell script that scans all files in destination and generate a report of all time-stamps  Some performance tips from my history with it and so many tests  amp  troubles     Despite of what most users online advise to use maximum threads  quot  MT 128 quot  like it s a general trick to get the best performance     PLEASE DON T USE  quot  MT 128 quot  WITH VERY LARGE FILES     that s a big mistake and it will decrease your drive performance dramatically after several runs    it will create very high fragmentation or even cause the files system to fail in some cases and you end up spending valuable time trying to recover a RAW partition and all that nonsense  And above all that  It will perform 4-6 times slower   For very large files   Use Only  quot One quot  thread  quot  MT 1 quot    Impact  BIG Must use  quot  J quot  to disable buffering    Impact  High Use  quot  NP quot  with  quot  LOG file quot  and Don t output to the console by  quot  TEE quot    Impact  Medium  Put the  quot  LOG file quot  on a separate drive from the source or destination   Impact  Low   For regular big files   Use multi threads  I would not exceed  quot  MT 4 quot    Impact  BIG IF destination disk has low Cache specs use  quot  J quot  to disable buffering   Impact  High  amp  4 same as above   For thousands of tiny files   Go nuts    with Multi threads  at first I would start with 16 and multibly by 2 while monitoring the disk performance  Once it starts dropping I ll fall back to the prevouse value and stik with it   Impact  BIG Don t use  quot  J quot    Impact  High Use  quot  NP quot  with  quot  LOG file quot  and Don t output to the console by  quot  TEE quot    Impact  HIGH  Put the  quot  LOG file quot  on a separate drive from the source or destination   Impact  HIGH

User · Answer

From the documentation       is Includes the same files     it Includes  tweaked  files     Same files  means files that are identical  name  size  times  attributes    Tweaked files  means files that have the same name  size  and times  but different attributes   robocopy src dst sample txt  is        copy if attributes are equal robocopy src dst sample txt  it        copy if attributes differ robocopy src dst sample txt  is  it    copy irrespective of attributes   This answer on Super User has a good explanation of what kind of files the selection parameters match   With that said  I could reproduce the behavior you describe  but from my understanding of the documentation and the output robocopy generated in my tests I would consider this a bug   PS C  temp  New-Item src -Type Directory   null PS C  temp  New-Item dst -Type Directory   null PS C  temp  New-Item src sample txt -Type File -Value  test001    null PS C  temp  New-Item dst sample txt -Type File -Value  test002    null PS C  temp  Set-ItemProperty src sample txt -Name LastWriteTime -Value  2016 1 1 15 00 00  PS C  temp  Set-ItemProperty dst sample txt -Name LastWriteTime -Value  2016 1 1 15 00 00  PS C  temp  robocopy src dst sample txt  is  it  copyall  mir       Options    S  E  COPYALL  PURGE  MIR  IS  IT  R 1000000  W 30  ------------------------------------------------------------------------------                             1    C  temp src              Modified                   7        sample txt  ------------------------------------------------------------------------------                 Total    Copied   Skipped  Mismatch    FAILED    Extras     Dirs           1         0         0         0         0         0    Files           1         1         0         0         0         0    Bytes           7         7         0         0         0         0     PS C  temp  robocopy src dst sample txt  is  it  copyall  mir       Options    S  E  COPYALL  PURGE  MIR  IS  IT  R 1000000  W 30  ------------------------------------------------------------------------------                             1    C  temp src              Same                       7        sample txt  ------------------------------------------------------------------------------                 Total    Copied   Skipped  Mismatch    FAILED    Extras     Dirs           1         0         0         0         0         0    Files           1         1         0         0         0         0    Bytes           7         7         0         0         0         0     PS C  temp  Get-Content   src sample txt test001 PS C  temp  Get-Content   dst sample txt test002  The file is listed as copied  and since it becomes a same file after the first robocopy run at least the times are synced  However  even though seven bytes have been copied according to the output no data was actually written to the destination file in both cases despite the data flag being set  via  copyall   The behavior also doesn t change if the data flag is set explicitly   copy d    I had to modify the last write time to get robocopy to actually synchronize the data   PS C  temp  Set-ItemProperty src sample txt -Name LastWriteTime -Value  Get-Date  PS C  temp  robocopy src dst sample txt  is  it  copyall  mir       Options    S  E  COPYALL  PURGE  MIR  IS  IT  R 1000000  W 30  ------------------------------------------------------------------------------                             1    C  temp src  100         Newer                      7        sample txt  ------------------------------------------------------------------------------                 Total    Copied   Skipped  Mismatch    FAILED    Extras     Dirs           1         0         0         0         0         0    Files           1         1         0         0         0         0    Bytes           7         7         0         0         0         0     PS C  temp  Get-Content   dst sample txt test001  An admittedly ugly workaround would be to change the last write time of same tweaked files to force robocopy to copy the data    amp  robocopy src dst  is  it  l  ndl  njh  njs  ns  nc     Where-Object      Trim         ForEach-Object        f   Get-Item         f LastWriteTime    f LastWriteTime AddSeconds 1       amp  robocopy src dst  copyall  mir   Switching to xcopy is probably your best option    amp  xcopy src dst  k r e i s c h f o x y

User · Answer

I did this for a home folder where all the folders are on the desktops of the corresponding users  reachable through a shortcut which did not have the appropriate permissions  so that users couldn t see it even if it was there  So I used Robocopy with the parameter to overwrite the file with the right settings   FOR  F  tokens     G IN   dir  b   DO robocopy     server02 Folder with shortcut     server02 home  G Desktop   S  A  V  log  C  RobocopyShortcut txt  XF   url   mp3   hta   htm   mht   js   IE5   css   temp   html   svg   ocx   3gp   opus   zzzzz   avi   bin   cab   mp4   mov   mkv   flv   tiff   tif   asf   webm   exe   dll   dl    oc    ex    sy    sys   msi   inf   ini   bmp   png   gif   jpeg   jpg   mpg   db   wav   wma   wmv   mpeg   tmp   old   vbs   log   bat   cmd   zip  SEC  IT  ZB  R 0   As you see there are many file types which I set to ignore  just in case   just set them for your needs or your case scenario   It was tested on Windows Server 2012  and every switch is documented on Microsoft s sites and others

[windows] How do I force Robocopy to overwrite files?

For very large files:

For regular big files:

For thousands of tiny files:

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