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Automatic deletion of old files when disk is full

I am using the "motion" software to capture still images to a volume of limited size. The images are all roughly the same file size, and are in one directory. Since they will be triggered by movement in the camera view, the creation of the files will be random and sporadic.

I would like to set it up so that, when the volume is full, the oldest files will be deleted to make room for the new files. I was thinking of writing a script that would monitor the directory on a regular basis. When the amount of free space drops below 100MB, it would delete enough files to clear up 200MB of free space. (or something along those lines)

I figure that somebody has had a need to do something like this before, but I haven’t been able to find anything as of yet. Any suggestions?

Thanks.

You can set script for this.

Thanks

You could use the logrotate tool, which can be used to manage files generally, or set a cron job to use the find cmd, after using eg df to check disk space.
These will be useful
http://rute.2038bug.com/index.html.gz
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html
http://www.tldp.org/LDP/abs/html/

Better u need to use the script to delet the old file by the find command with option mtime or atime and schedule it by cronjob to run as per frequency of the file .

I figured somebody would have done this before, but I guess not. So, I wrote a script to do the trick:

Code:



#!/bin/bash



# Immediately exit upon shell error

set -e



# Set lock file details

scriptname=$(basename $0)

lock="/var/run/${scriptname}"



# Lock the process, or exit if already running

exec 200>$lock

flock -n 200 || exit 1



# Write the PID to the lock file

pid=$$

echo $pid 1>&200



# Define the location of the applications

DF="/bin/df"

AWK="/usr/bin/awk"

SED="/bin/sed"

FIND="/usr/bin/find"



# Define the directory to check

DIR="/motion"



# Define constants

Minimum=100  # Minimum space below which files will be deleted (MB)

DeleteTo=200  # Delete files until this value is reached (MB)

NumtoDel=100  # Number of files to delete between each free disk space check



# Set shell such that empty file listing will return null

shopt -s nullglob



# Check if free space is less than the minimum specified

FreeSpace=$($DF -m $DIR | $AWK '{print $4}' | $SED "1d")

if [ $FreeSpace -lt $Minimum ]; then

  # Free space has dropped below minimum value, delete files until DeleteTo space is free

  while [ $FreeSpace -lt $DeleteTo ]; do

    # Check if any pictures remain in the directory, otherwise break out of the delete loop

    if test -z "$($FIND $DIR -maxdepth 1 -name '*.jpg' -print -quit)"; then

      break

    fi

    # Delete files until NumtoDel has been reached, or no more files exist

    FileCount=0;

    for FileName in $DIR/*.jpg; do

      rm $FileName

      FileCount=$((FileCount+1))

      # Check if number of files to delete has been reached

      if [ $FileCount -ge $NumtoDel ]; then

        break

      fi

    done

    # Check if free space is less than the minimum specified

    FreeSpace=$($DF -m $DIR | $AWK '{print $4}' | sed "1d")

  done

fi

Basically, you set the minimum free space available to the constant Minimum in the script. When less than this value is free, it will delete files in groups of NumtoDel until DeleteTo MB are free.

I set it to run every 5 minutes. Seems to work fine so far.

Thanks for the help.