Have you ever arrived at work to find the Exchange backup hasn't run over the weekend, the logs volume is out of space, and the Storage Group is off line?  This little utility will prevent this from happening by NTFS compressing the oldest logs until the free space is at an acceptable limit to run a backup and clear down the logs.

Note that to restore an exchange full backup you dont need the logs.  If you do an incremental/differential backup however, you may need to compress some or all of them to make the logs fit during a restore.

Schedule this to run every 30 minutes, and it will check the space threshold and if necessary, compress enough files to keep the free space above the threshold.

MAKESPACE.CMD:

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@echo off

rem this will determine the free space of the Log volume and compress the oldest logs until

rem the free space is above the set threshold.

rem Written by Leon Funnell 04/04/2005

setlocal

rem change the values below to suit your configuration:

rem the threshold is in bytes - example below is 4GB

set threshold=4000000000

set DriveToMonitor=L:

set FolderToCompress=L:\exchsrvr\mdbdata

set FilesToCompress=*.log

echo Monitoring %DriveToMonitor% for threshold %threshold% bytes

rem Sets the variable freespace to the space available on DriveToMonitor

call :freespace q:

if /i "%freespace"% geq "%threshold%" goto :done

echo Free Space is %freespace% bytes - We need to compress some files!

echo Compressing %FolderToCompress%\%FilesToCompress%

for /f "delims=\" %%i in ('dir %FolderToCompress%\%FilesToCompress% /b /od') do call :testCompressed "%FolderToCompress%\%%i" %threshold% %DriveToMonitor%

goto :done

:done

call :freespace %DriveToMonitor%

echo Free Space on %DriveToMonitor% is OK -    %freespace% bytes

endlocal

goto :eof

rem --------------------------------------------------------------------------------------

:testCompressed

rem Tests if the file passed is compressed

call :freespace %3

if /i "%freespace%" geq "%2" goto :eof

compact /a %1 | find "=" | find "1   " > nul

if ERRORLEVEL 1 goto :eof

if ERRORLEVEL 0 call :CompressFiles %1 %2 %3

goto :eof

rem --------------------------------------------------------------------------------------

:CompressFiles

Rem Compresses files until threshold is reached then exits

call :freespace %3

if /i "%freespace%" geq "%2" goto :eof

echo Compacting %1

compact /c %1 >nul

goto :eof

rem --------------------------------------------------------------------------------------

:freespace

Rem finds free space of given drive

for /f "tokens=3,4,5" %%a in ('dir %1 /-c') do if "%%b %%c"=="bytes free" set freespace=%%a

goto :eof