Robocopy

  • To use the Robocopy multithreaded feature to copy files and folders to another drive faster, use these steps: Open Start on Windows 10. Search for Command Prompt, right-click the result, and select the Run as administrator option. Type the following command to copy the files and folders to another drive and press Enter.
  • Robocopy has existed since NT4 days in 1996, so this is likely not the first time you are hearing of it. Back then and until 2008, it was available with the Windows Resource Kit download. Beginning in 2008 (and thereafter), it was bundled with both desktop and server operating systems starting with Vista and Server 2008.

Robust File and Folder Copy.
By default Robocopy will only copy a file if the source and destination have different time stamps or different file sizes.

## = New Option in Windows 8 and Windows 10.

Feb 03, 2021 To use the Robocopy multithreaded feature to copy files and folders to another drive faster, use these steps: Open Start on Windows 10. Search for Command Prompt, right-click the result, and select the Run as administrator option. Type the following command to copy the files and folders to another drive and press Enter.

Robocopy Download

Robocopy EXIT CODES

By copying only the files that have changed, robocopy can be used to backup very large volumes.

If either the source or desination are a 'quoted long foldername' do not include a trailing backslash as this will be treated as an escape character, i.e. 'C:some path' will fail but 'C:some path' or 'C:some path.' or 'C:some path' will work.

If creating a progress logfile with /LOG , specify a destination directory that already exists, robocopy will create the file but will not create a log directory automatically.

Long FileNames

ROBOCOPY will accept UNC pathnames including long pathnames over 256 characters long. When copying a tree of multiple files and subfolders, if the destination folder has a longer name than the source folder, then it is likely some files will hit the 256 character limit.
Even when Robocopy successfully copies such files, other software may refuse to open them.

For compatibility with old software the User Profile folder contains a number of Junction Points, 'Application Data', 'My Documents', Recent, 'Send To' etc.
By default RoboCopy /S will follow a junction point in the source and copy the contents to a standard folder in the destination.

In the case of 'Application Data' on Windows 7 Documents and Settings%USER%Application Data is a junction point to Users%USER%AppDataRoaming, which in turn can contain the Application Data junction as a subdirectory.

In cases like this RoboCopy can create a recursive loop copying the folder into itself until the NTFS max folder name length of 32,767 characters is exceded. To avoid this use the /XJ or /XJD option.

Symbolic Links and Junctions

/sl Will copy symbolic links, this will copy a File Symbolic Link only, creating a new symbolic link at the destination.

For a Directory Symbolic Link, a Junction, or a Hard Link, RoboCopy will follow the source and copy the contents to a standard folder in the destination. For a backup program this is usually the desired behaviour.

To exclude Junction points from being copied you can use the options /XJ, /XJD, /XJF this will prevent the source files from being copied. The Junction Point itself will not be copied (either with or without these flags).

An NTFS junction point in the Destination will not be deleted by RoboCopy, if you select any options which delete from the destination (/purge, /mir) and the destination contains a junction, RoboCopy will blindly follow that junction and delete the contents.
The /XJ options do not affect this as they only exclude junctions from the source.

File Attributes [RASHCNETO]

These options accept any combination of the following letters, when several are specified, will match if any or all items match:

Multithreaded copying with /MT:n will improve performance until the network and file system latency become the limiting factor, /MT:4 is a good place to start testing.

To limit the network bandwidth used by robocopy, specify the Inter-Packet Gap parameter /IPG:n
This will send packets of 64 KB each followed by a delay of n Milliseconds.

Robocopy will fail to copy files that are locked by other users or applications, so limiting the number of retries with /R:0 will speed up copying by skipping any in-use files. The Windows Volume Shadow Copy service is the only Windows subsystem that can copy open files. Robocopy does not use the Volume Shadow Copy service, but it can backup a volume shadow that has already been created with VSHADOW or DISKSHADOW.

All versions of Robocopy will copy security information (ACLs) for directories, version XP010 will not copy file security changes unless the file itself has also changed, this greatly improves performance.

/REG Writes to the registry at HKCUSoftwareMicrosoftResKitRobocopy

/XX (exclude extra) If used in conjunction with /Purge or /Mir, the exclude extra switch will take precedence and prevent any files being deleted from the destination.

/B (backup mode) will allow Robocopy to override file and folder permission settings (ACLs).

To run ROBOCOPY under a non-administrator account will require SeBackupPrivilege (backup files privilege), to copy security information auditing privilege is also required, plus of course you need at least read access to the files and folders.

ERROR 5 (0x00000005) Changing File Attributes ... Access is denied
This error usually means that File/Folder permissions or Share permissions on either the source or the destination are preventing the copy, either change the permissions or run the command in backup mode with /B.

Robocopy

Robocopy 'Jobs' and the 'MOnitor source' option provide an alternative to setting up a Scheduled Task to run a batchfile with a Robocopy command.

Robocopy Examples

Examples:

Teracopy

Simple copy of all files from one folder to another:

Copy all .jpg and .bmp files from one folder to another:

Copy files including subfolders (even empty ones /E)
If this command is run repeatedly it will skip any files already in the destination, however it is not a true mirror as any files deleted from the source will remain in the destination.

List files over 32 MBytes in size:

Move files over 14 days old: (note the MOVE option will fail if any files are open and locked.)

Backup a Server:
The script below copies data from FileServ1 to FileServ2, the destination holds a full mirror along with file security info. When run regularly to synchronize the source and destination, robocopy will only copy those files that have changed (change in time stamp or size).

@ECHO OFF
SETLOCAL

SET _source=FileServ1e$users

SET _dest=FileServ2e$BackupUsers

SET _what=/COPYALL /B /MIR
:: /COPYALL :: COPY ALL file info
:: /B :: copy files in Backup mode.
:: /MIR :: MIRror a directory tree
SET _options=/R:0 /W:0 /LOG:C:batchRoboLog.txt /NFL /NDL
:: /R:n :: number of Retries
:: /W:n :: Wait time between retries
:: /LOG :: Output log file
:: /NFL :: No file logging
:: /NDL :: No dir logging
ROBOCOPY %_source% %_dest% %_what% %_options%

Run two robocopy jobs at the same time with START /Min

Copy only permission changes (additions and removals) assuming we already have a copy of the data:
ROBOCOPY FileServerC$ SVR-Backupsc$Backups /E /Copy:S /IS /IT

Robocopy

Availability

Robocopy

Robocopy XP027 is a standard command in Windows 7 and above. Robocopy does not run on Windows 95, or NT 3.5. (Robocopy is a Unicode application). The Microsoft Robocopy GUI will install Robocopy XP026 to C:Windowssystem32, this version can can run on older OS's, and includes some features from XP027 (/BYTES) but has competely broken errorlevel handling.

Bugs

Robocopy /MOVE or /PURGE can be used to delete empty folders by setting source and destination to the same folder, but this does not always deal with nested empty folders in a single pass. It will work if Windows Explorer is closed.

When copying files larger than 2 GB from some iSCSI/SAN volumes the copy operation may fill all available RAM and then stall out. This typically happens when the RAID virtual disk on the controller is set to write-through caching rather than write-back caching.
Copy utilities such as TeraCopy ($) and BITS will workaround this issue because they copy the file in larger blocks, however the cost of this is that copying smaller files may then be slower than using Robocopy. The /IPG option may help with this issue.

Version XP026 returns a success errorlevel even when it fails.

“One, a robot may not injure a human being, or through inaction, allow a human being to come to harm” - Isaac Asimov, Laws of Robotics from I. Robot, 1950

Related commands:

Robocopy EXIT CODES
Robocopy /MIR switch – Security changes added to Robocopy in Windows Vista.
Set-LastWrite - Reset Folder 'Last Modified' to the most recent file in the folder (PowerShell function).
DiskShadow - Copy open files (Shadow copies).
COPY - Copy one or more files to another location.
Robocopy GUI - Technet magazine (installs Robocopy XP026).
RichCopy free GUI copy utility - Ken Tamaru [MSFT].
DelTree - Delete subfolders and files / delete empty folders.
Convert KB/MB - Bits and Bytes, bandwidth calculations .
Q323275 - Copy Security info without copying files (/SECFIX or /COPY:S).
Equivalent PowerShell command: BITS cmdlets - Background Intelligent Transfer Service.
Equivalent bash command: rsync - Remote file copy (Synchronize file trees).

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Copies file data from one location to another.

Syntax

For example, to copy a file named yearly-report.mov from c:reports to a file share marketingvideos while enabling multi-threading for higher performance (with the /mt parameter) and the ability to restart the transfer in case it's interrupted (with the /z parameter), type:

Parameters

ParameterDescription
<source>Specifies the path to the source directory.
<destination>Specifies the path to the destination directory.
<file>Specifies the file or files to be copied. Wildcard characters (* or ?) are supported. If you don't specify this parameter, *.* is used as the default value.
<options>Specifies the options to use with the robocopy command, including copy, file, retry, logging, and job options.

Copy options

OptionDescription
/sCopies subdirectories. This option automatically excludes empty directories.
/eCopies subdirectories. This option automatically includes empty directories.
/lev:<n>Copies only the top n levels of the source directory tree.
/zCopies files in restartable mode. In restartable mode, should a file copy be interrupted, Robocopy can pick up where it left off rather than re-copying the entire file.
/bCopies files in backup mode. Backup mode allows Robocopy to override file and folder permission settings (ACLs). This allows you to copy files you might otherwise not have access to, assuming it's being run under an account with sufficient privileges.
/zbCopies files in restartable mode. If file access is denied, switches to backup mode.
/jCopies using unbuffered I/O (recommended for large files).
/efsrawCopies all encrypted files in EFS RAW mode.
/copy:<copyflags>Specifies which file properties to copy. The valid values for this option are:
  • D - Data
  • A - Attributes
  • T - Time stamps
  • S - NTFS access control list (ACL)
  • O - Owner information
  • U - Auditing information
The default value for this option is DAT (data, attributes, and time stamps).
/dcopy:<copyflags>Specifies what to copy in directories. The valid values for this option are:
  • D - Data
  • A - Attributes
  • T - Time stamps
The default value for this option is DA (data and attributes).
/secCopies files with security (equivalent to /copy:DATS).
/copyallCopies all file information (equivalent to /copy:DATSOU).
/nocopyCopies no file information (useful with /purge).
/secfixFixes file security on all files, even skipped ones.
/timfixFixes file times on all files, even skipped ones.
/purgeDeletes destination files and directories that no longer exist in the source. Using this option with the /e option and a destination directory, allows the destination directory security settings to not be overwritten.
/mirMirrors a directory tree (equivalent to /e plus /purge). Using this option with the /e option and a destination directory, overwrites the destination directory security settings.
/movMoves files, and deletes them from the source after they are copied.
/moveMoves files and directories, and deletes them from the source after they are copied.
/a+:[RASHCNET]Adds the specified attributes to copied files. The valid values for this option are:
  • R - Read only
  • A - Archive
  • S - System
  • H - Hidden
  • C - Compressed
  • N - Not content indexed
  • E - Encrypted
  • T - Temporary
/a-:[RASHCNET]Removes the specified attributes from copied files. The valid values for this option are:
  • R - Read only
  • A - Archive
  • S - System
  • H - Hidden
  • C - Compressed
  • N - Not content indexed
  • E - Encrypted
  • T - Temporary
/createCreates a directory tree and zero-length files only.
/fatCreates destination files by using 8.3 character-length FAT file names only.
/256Turns off support for paths longer than 256 characters.
/mon:<n>Monitors the source, and runs again when more than n changes are detected.
/mot:<m>Monitors the source, and runs again in m minutes, if changes are detected.
/MT[:n]Creates multi-threaded copies with n threads. n must be an integer between 1 and 128. The default value for n is 8. For better performance, redirect your output using /log option.

The /mt parameter can't be used with the /ipg and /efsraw parameters.

/rh:hhmm-hhmmSpecifies run times when new copies may be started.
/pfChecks run times on a per-file (not per-pass) basis.
/ipg:nSpecifies the inter-packet gap to free bandwidth on slow lines.
/slDon't follow symbolic links and instead create a copy of the link.
/nodcopyCopies no directory info (the default /dcopy:DA is done).
/nooffloadCopies files without using the Windows Copy Offload mechanism.
/compressRequests network compression during file transfer, if applicable.

Important

When using the /secfix copy option, specify the type of security information you want to copy, using one of these additional copy options:

  • /copyall
  • /copy:o
  • /copy:s
  • /copy:u
  • /sec

File selection options

OptionDescription
/aCopies only files for which the Archive attribute is set.
/mCopies only files for which the Archive attribute is set, and resets the Archive attribute.
/ia:[RASHCNETO]Includes only files for which any of the specified attributes are set. The valid values for this option are:
  • R - Read only
  • A - Archive
  • S - System
  • H - Hidden
  • C - Compressed
  • N - Not content indexed
  • E - Encrypted
  • T - Temporary
  • O - Offline
/xa:[RASHCNETO]Excludes files for which any of the specified attributes are set. The valid values for this option are:
  • R - Read only
  • A - Archive
  • S - System
  • H - Hidden
  • C - Compressed
  • N - Not content indexed
  • E - Encrypted
  • T - Temporary
  • O - Offline
/xf <filename>[ ...]Excludes files that match the specified names or paths. Wildcard characters (* and ?) are supported.
/xd <directory>[ ...]Excludes directories that match the specified names and paths.
/xcExcludes changed files.
/xnExcludes newer files.
/xoExcludes older files.
/xxExcludes extra files and directories.
/xlExcludes 'lonely' files and directories.
/imInclude modified files (differing change times).
/isIncludes the same files.
/itIncludes tweaked files.
/xcExcludes existing files with the same timestamp, but different file sizes.
/xnExcludes existing files newer than the copy in the source directory.
/xoExcludes existing files older than the copy in the source directory.
/xxExcludes extra files and directories present in the destination but not the source. Excluding extra files will not delete files from the destination.
/xlExcludes 'lonely' files and directories present in the source but not the destination. Excluding lonely files prevents any new files from being added to the destination.
/isIncludes the same files. Same files are identical in name, size, times, and all attributes.
/itIncludes 'tweaked' files. Tweaked files have the same name, size, and times, but different attributes.
/max:<n>Specifies the maximum file size (to exclude files bigger than n bytes).
/min:<n>Specifies the minimum file size (to exclude files smaller than n bytes).
/maxage:<n>Specifies the maximum file age (to exclude files older than n days or date).
/minage:<n>Specifies the minimum file age (exclude files newer than n days or date).
/maxlad:<n>Specifies the maximum last access date (excludes files unused since n).
/minlad:<n>Specifies the minimum last access date (excludes files used since n) If n is less than 1900, n specifies the number of days. Otherwise, n specifies a date in the format YYYYMMDD.
/xjExcludes junction points, which are normally included by default.
/fftAssumes FAT file times (two-second precision).
/dstCompensates for one-hour DST time differences.
/xjdExcludes junction points for directories.
/xjfExcludes junction points for files.

Retry options

OptionDescription
/r:<n>Specifies the number of retries on failed copies. The default value of n is 1,000,000 (one million retries).
/w:<n>Specifies the wait time between retries, in seconds. The default value of n is 30 (wait time 30 seconds).
/regSaves the values specified in the /r and /w options as default settings in the registry.
/tbdSpecifies that the system will wait for share names to be defined (retry error 67).

Logging options

OptionDescription
/lSpecifies that files are to be listed only (and not copied, deleted, or time stamped).
/xReports all extra files, not just those that are selected.
/vProduces verbose output, and shows all skipped files.
/tsIncludes source file time stamps in the output.
/fpIncludes the full path names of the files in the output.
/bytesPrints sizes, as bytes.
/nsSpecifies that file sizes are not to be logged.
/ncSpecifies that file classes are not to be logged.
/nflSpecifies that file names are not to be logged.
/ndlSpecifies that directory names are not to be logged.
/npSpecifies that the progress of the copying operation (the number of files or directories copied so far) will not be displayed.
/etaShows the estimated time of arrival (ETA) of the copied files.
/log:<logfile>Writes the status output to the log file (overwrites the existing log file).
/log+:<logfile>Writes the status output to the log file (appends the output to the existing log file).
/unicodeDisplays the status output as Unicode text.
/unilog:<logfile>Writes the status output to the log file as Unicode text (overwrites the existing log file).
/unilog+:<logfile>Writes the status output to the log file as Unicode text (appends the output to the existing log file).
/teeWrites the status output to the console window, as well as to the log file.
/njhSpecifies that there is no job header.
/njsSpecifies that there is no job summary.

Job options

OptionDescription
/job:<jobname>Specifies that parameters are to be derived from the named job file.
/save:<jobname>Specifies that parameters are to be saved to the named job file.
/quitQuits after processing command line (to view parameters).
/nosdIndicates that no source directory is specified.
/noddIndicates that no destination directory is specified.
/ifIncludes the specified files.

Exit (return) codes

ValueDescription
0No files were copied. No failure was encountered. No files were mismatched. The files already exist in the destination directory; therefore, the copy operation was skipped.
1All files were copied successfully.
2There are some additional files in the destination directory that are not present in the source directory. No files were copied.
3Some files were copied. Additional files were present. No failure was encountered.
5Some files were copied. Some files were mismatched. No failure was encountered.
6Additional files and mismatched files exist. No files were copied and no failures were encountered. This means that the files already exist in the destination directory.
7Files were copied, a file mismatch was present, and additional files were present.
8Several files did not copy.
Robocopy

Note

Any value greater than 8 indicates that there was at least one failure during the copy operation.

Additional References