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Using the FORFILES Command to Delete SQL Server Backups
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By: Tim Ford | Read Comments (8) | Related Tips: More > Backup |
Problem
Recently I constructed a new backup process that I want to institute globally across all my SQL Server 2005 instances. This backup process will not only backup all the databases I point it towards, but at the same time will script out the backup commands to a single file in the format of F_YYYYMMDD.sql if the backup process is a full database backup or D|T_YYMMDD_HHMMSS.sql if the backup process is a differential (D) or transaction log (T) backup. These script files are then stored in a subfolder under the backup directory on the SQL Server. The process works great, but I only don't want to keep every .sql file. I cant see the need to keep these scripts after 30 days. Is there a way I can automate a file deletion process from within SQL Server?
Solution
While there are many ways the file deletion process can be handled with T-SQL code. I use the xp_cmdshell command along with the FORFILES command for a very similar process to what you have outlined. Solid information of FORFILES is available from Microsoft TechNet, but I will touch on much of the structure and use of FORFILES for your purposes in this tip.
The FORFILES command will select a subset of files and execute a command against the set. The command requires the following parameters and accepts the following variables:
Parameters
| Parameter Name | Description |
| /p | Path |
| /m | Search Mask (default is *.*) |
| /s | Subdirectories will be searched recursively if this parameter is included |
| /c <command> | Command to be executed against each file in the result set, commands must be enclosed in double-quotes, default is "cmd c/ echo @file" |
| /d | Date range for file selection, using Last Modified Date as the criterion for the file. When the /d parameter is in the form of MM/DD/YYYY, file meeting the criteria of +/- the specified date are included. When in the format of a smallint (-32,768 - 32,768) the files +/- the files with a modified date +/- that number of days from the current date are included in the file result set. |
Variables
| Variable Name | Description |
| @FILE | File name |
| @FNAME | File name without extension |
| @EXT | File extension |
| @PATH | Full path of the file |
| @RELPATH | Relative path of the file |
| @ISDIR | Evaluates as TRUE if the file type is a directory |
| @FSIZE | File size in bytes |
| @FDATE | Last modified date stamp on the file |
| @FTIME | Last modified timestamp on the file |
Using these parameters the following examples could be constructed to take care of your dilemma for deleting your backup script files. You can create scripts based upon modification date/time or backup type. You can even construct scripts that utilize both criteria. We will now take a closer look at these potential scripts. Remember that you will be executing these from within T-SQL code, so you will need to wrap the statements within an xp_cmdshell call in the format of EXEC xp_cmdshell 'FORFILES COMMAND'. Please note that in all examples I am using the /Q and /F flags for the del command. These signify that the command will use quiet mode (/Q) and will even delete read-only files (/F).
Examples
Delete all .sql files in the C:\Backup directory and its subfolders where the file modified date is older than 10/18/2008.
| EXEC xp_cmdshell 'FORFILES /p c:\BACKUP /s /m *.sql /d 10/18/2008 /c "CMD /C del /Q /F @FILE"' |
Delete all .sql files in the C:\Backup directory and its subfolders where the file modified date is more than 30 days old.
| EXEC xp_cmdshell 'FORFILES /p c:\BACKUP /s /m *.sql /d -30 /c "CMD /C del /Q /F @FILE"' |
Delete all .sql files in the C:\Backup directory and its subfolders where the file modified date is more than 30 days old and the file name starts with an "F_".
| EXEC xp_cmdshell 'FORFILES /p c:\BACKUP /s /m F_*.sql /d -30 /c "CMD /C del /Q /F @FILE"' |
Next Steps
- Modify the code above to fit your retention policy, file structure and needs.
- Add the modified code to a subsequent job step in the SQL Agent job that runs your backup process. Include verbose SQL Agent job logging to verify that the process is working correctly.
- Keep in mind that the FORFILES command does a lot more than just deleting files. As an example, it can be used to list files for other processes as well.
- Review other file deletion automation tips from MSSQLTips.com.
- Review tips on xp_cmdshell at MSSQLTips.com
Last Update: 11/3/2008
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Comments and Feedback:
| Tuesday, November 11, 2008 - 8:09:09 AM - jerryhung | Read The Tip |
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Sadly FORFILES does not work with UNC (Network Path) and I had to resort to VBScript for a job to cleanup backup files
But for local cleanup, FORFILES is much cleaner and better to use |
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| Tuesday, May 29, 2012 - 1:19:57 PM - mike B | Read The Tip |
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this actually works using all SQL
http://www.sqlservercentral.com/scripts/Administration/62729/
Just sayin... |
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| Tuesday, May 29, 2012 - 2:11:40 PM - Greg Robidoux | Read The Tip |
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@mike B - the link you provided actually uses xp_cmshell as well. Instead of using "FOREFILES" it is using "DEL" to delete the files. Here are a couple of other options:
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| Tuesday, May 29, 2012 - 3:38:11 PM - Michael B | Read The Tip |
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Yes, the thing is forfiles will not work on UNC... This way you dont have to program in VB/CLR or whatever AND use UNC |
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| Tuesday, May 29, 2012 - 4:02:06 PM - Greg Robidoux | Read The Tip |
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Got it. Makes sense on the UNC issue. |
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| Saturday, June 23, 2012 - 3:45:30 PM - Ken | Read The Tip |
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Hi Tim,
I have tried your code and it does not seem to be working...I have sql backup files that are older than 2 days and I am running this command in SQL Server Agent as a Job Step...Below is my code...Any suggestions? Many thanks! The SQL Agent says the job executed with no errors but the files still remain in the folder....
EXEC xp_cmdshell 'FORFILES /p D:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\Backup /s /m *.bak /d-2 /c "CMD /C del /Q /F @FILE"' |
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| Tuesday, June 26, 2012 - 6:24:21 PM - Ken | Read The Tip |
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Hi Tim and All For some reason, the above code never worked for me...I kept playing with it and found a tip at another site. The following line of code now works! Make sure that the "" are implemented before and end of the file location path as well as on the file type.
EXEC xp_cmdshell 'FORFILES /p "D:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\Backup" /s /m "*.bak" /d -3 /c "CMD /C del /Q /F @FILE"' |
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| Thursday, September 27, 2012 - 12:27:45 PM - Will S | Read The Tip |
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Example of how to get around the UNC limitation using PUSHD DOS command: http://www.sqlservercentral.com/Forums/Topic1237283-391-2.aspx
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