backup · Windows · Windows Vista

Robocopy Basics


When it comes to copying large amounts or large in size files and directories many people don’t realise there are better tools for the job then the built in File Explorer used by Windows. Robocopy is a free command line application created by Microsoft that is perfect for copying large or even huge amounts of data between hard drives or over networks.

Robocopy or ‘Robust File Copy’ was first introduced as part of the Windows Resource Kit but has now been included as default in copies of Windows Vista. So what makes robocopy a better choice then either Windows Explorer, copy or the old DOS xcopy command?

Pros:

  • It can tolerate network outages, retry and attempt to resume the file transfer a set number of times making it perfect for wireless connections.
  • Can copy all NTFS attributes including owner and auditing information.
  • Has a mirror mode to synchronise the target directory with the source making them identical.
  • Uses a detailed verbose mode that keeps you up to date with all the active transfers.
  • Is robust and quick, enabling the transferring of many gigabytes worth of data.
  • You can throttle it’s bandwidth usage so the file transfers do not hog the network connection.
  • Can copy copy destination content of symbolic links.

Cons:

  • It uses the command prompt and has a myriad of options that can be confusing for the first time user.
  • You can only copy directories, not individual files (though you can filter out or in types and names of files you don’t want transferred).

Here are a few common attributes I use with Robocopy.

Mirroring a directory with a UNC (network connection) target

robocopy "c:\my source directory" "\\Server\my target directory" /MIR /XF *.bak *.tmp /XA:ST /W:5 /R:5

/MIR MIRrors a directory
/XF *.bak or *.tmp Excludes files, in this case anything that has the extensions .bak or .tmp
/XA:ST Exclude files with either System or Temporary attributes
/W:5 Wait 5 seconds between retries (default is 30 seconds)
/R:5 Attempt up to 5 retries on a failed copy (default is normally a million)

If you have shortcuts within your directories and you don’t don’t their destination content transferred you can also use the /XJ attribute which ‘excludes Junction points’

And if you wanted to copy all the file and directory security details you can use /SEC

Copying files within an age bracket

robocopy "c:\my photos" "d:\my recent photos" /NOCOPY /MAXAGE:30 /R:0

Now while the first example used an UNC target but this doesn’t have to be the case. Here we are copying to a different hard drive on the same computer and we’re filtering the files by an age group.

/NOCOPY Ignores the individual file attributes and copies only the files themselves.
/MAXAGE:30 Only copies files that are 30 days old or less.
/R:0 Zero number of retries means if an error is encountered robocopy will skip it and just continue onto the next file.

This is result after I copied over 11,600 images (nearly 28gigs worth) over a 100Mbps ethernet connection using robocopy

Try that with XP’s built in Explorer and you won’t get very far.

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6 thoughts on “Robocopy Basics

  1. In some cases the /NOCOPY attribute causes robocopy to generate only directories without file content. I use the XP026 version of robocopy. I have see this issue on a transfer from NTFS to EXT3 remote network drive and from NTPS to NTFS USB 2.0 local drive. I think this problem is due to protection policies of the target drive.

  2. Have you used xcopy. This built in windows command too is good for copying large data with multiple folders and files.

  3. Thanks for the information… I used it to backup a user profile to an external HD from the command prompt in the Vista repair disc… backup and reload! Thanks for the tips…

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