Friday, 10 February 2012

A simple script to use either robocopy or xcopy to backup files

Under various circumstances, I've found it useful to cobble together a script to do a sync backup across the network from one Windows server to another. Usually this is for files only and is for either a mirror or a daily, full backup of data. Obviously there are some great backup tools available that make something like this largely unnecessary, however, this is quick, simple and gives you an email output of what has happened. The first example below uses robocopy (Robust Copy) which is a very nice bit of kit indeed. It's a bit more useful than xcopy and handles larger numbers of files better. Don't get me wrong, I love xcopy, but it has it's limitations. I use rsync a lot on Linux servers and robocopy gives me many similar options for how I want to handle files.

The destination directory could be anything - another folder on the same PC, a removable disk, a mapped share or even a straight UNC path e.g. \\server\share - flexibility is the key for this script, once the basic variables are right and you've decided to use robocopy or xcopy then off you go.

So to the script:

Open notepad and put this info in - note where things are comments and what variables you'll have to change:

Script start:
echo on
REM Set up some time variables
for /f "Tokens=1-4 Delims=/ " %%i in ('date /t') do set dt=%%l-%%k-%%j
for /f "Tokens=1" %%i in ('time /t') do set tm=-%%i
set tm=%tm::=-%
set dtt=%dt%%tm%
REM set up variables for log files, source and destination - change this variable
set log="C:\Users\owner\Documents\Scripts\Logs\%dt%.log"
REM local stuff to be backed up - change this variable
set src="c:\documents"
REM remote location to put backups - change this variable
set dest="I:\backups\server"
REM now for the actual work - change switches as required - explanation of switches is below.
robocopy %src% %dest% /E /Z /MIR /R:1 /LOG:%log%
REM I'd like to know how it went (this file can be big if there are a lot of files copied)
echo Backup Logs attached | blat - -subject "Sync Log Report for %dt%" -to "" -attach %log% -f

Use blat to send the email - grab it from (great program!) It sends an email with a header that will look like this:
Sync Log Report for 2012-02-10
and an attachment of your log file. You can add different things to this - for example I'll often use a [servername] tag after the date.

The robocopy switches used are:

  • /E = copy sub-directories, including empty ones
  • /Z = copy files in restartable mode (in case the network drops out or something similar)
  • /MIR = MIRror a directory tree (which is /E plus /PURGE)
  • /R:1 = number of retries on failed copies. It's best to set this - by default it's 1 million (!)
I run this from the Windows Scheduler and have a mirrored copy of data files each night. It's quite a useful little tool. If you'd like to use xcopy instead there are a few things to consider:
  • the src and dest variables need to have a trailing backslash and a wildcard
    • set src="c:\documents\*"
    • set dest="i:\backups\server\*"
  • and the command to insert would be:
    • xcopy %src% %dest% /C /D /E /H /Y > %log%
    • where the switches are:
      • /C = continue copying even if there are errors
      • /D = copies files whose source is newer
      • /E = copies directories and sub-directories (even if empty)
      • /H = copies hidden and system files
      • /Y = suppresses prompting to overwrite files
    • the > redirects xcopy's output to the %log% variable we configured earlier in the script, and then blat will email the resulting file out.
If you find this useful in anyway, please let me know in the comments.