SwapClean - Revision history

Smsldoo at 14:33, 25 March 2014

2014-03-25T14:33:07Z

Smsldoo at 17:41, 17 February 2012

2012-02-17T17:41:05Z

10.30.6.195: /* Script */

2011-06-03T14:47:00Z

‎Script

10.30.6.195: /* Script */

2011-06-03T14:17:31Z

‎Script

10.30.6.195: /* Script */

2011-06-03T13:33:53Z

‎Script

10.30.6.195: /* Script */

2011-06-03T13:24:22Z

‎Script

10.30.6.195: /* loadthresh */

2011-06-02T18:26:38Z

‎loadthresh

10.30.6.195: /* Script */

2011-06-02T18:25:54Z

‎Script

10.30.6.195: /* Script */

2011-04-16T16:21:40Z

‎Script

10.30.6.195: /* Script */

2011-04-15T16:08:11Z

‎Script

@@ Line 4: / Line 4: @@
 ==Script==
 #!/bin/bash
 #Swap Cleaner
@@ Line 143: / Line 142: @@
                  ;;
    esac
-</code>
+</source>
 ==What to change==

← Older revision		Revision as of 17:41, 17 February 2012
Line 1:		Line 1:
		+	[[Category:Scripts]]
	==Overview==		==Overview==
	Script that is run via cron every ~10 minutes. Main purpose is to clear any swap usage if the system has the enough free ram and load is below a set value.		Script that is run via cron every ~10 minutes. Main purpose is to clear any swap usage if the system has the enough free ram and load is below a set value.

@@ Line 4: / Line 4: @@
 ==Script==
 <code>[bash,n]
 #!/bin/bash
 #Swap Cleaner
@@ Line 30: / Line 32: @@
 function clearswap {
 	plog "Clearing swap"
-	touch .swapoff
+	touch /var/run/.swapoff
-	echo $$ > .swapoff
+	echo $$ > /var/run/.swapoff
 	/sbin/swapoff -a && /sbin/swapon -a
-	rm -f .swapoff
+	rm -f /var/run/.swapoff
 	plog "Swap Cleared"
 	return
@@ Line 56: / Line 58: @@
 			then
 				#Load is below threshold
-				if [ ! -e ".swapoff" ]
+				if [ ! -e "/var/run/.swapoff" ]
 				then
 					clearswap
 				else
 					plog "Lock file found, swap may be already clearing"
-					opid=`cat .swapoff`
+					opid=`cat /var/run/.swapoff`
 					if [ ! "`ps ax | grep $opid | grep ${0##*/}`" ]
 					then
 						plog "PID not active or not owned by swapclean, clearing pid file"
-						rm -f .swapoff
+						rm -f /var/run/.swapoff
 						clearswap
 					else

@@ Line 25: / Line 25: @@
 		sed -i -e "1d" /var/log/swapclean
 	fi
 	return
+}
@@ Line 52: / Line 62: @@
 					plog "Lock file found, swap may be already clearing"
 					opid=`cat .swapoff`
-					if [ `ps ax | grep $opid | grep swapclean` -eq "" ]
+					if [ ! "`ps ax | grep $opid | grep ${0##*/}`" ]
 					then
 						plog "PID not active or not owned by swapclean, clearing pid file"
@@ Line 71: / Line 81: @@
+}
 function enablecron {
 	if [ -e "/etc/cron.d/swapclean.sh" ]
@@ Line 134: / Line 133: @@
 		echo " --cron [on, change, off]"
 		echo "	on: Turns on cron job and asks for time"
-		echo "  change: Changes the cron time"
+		echo "	change: Changes the cron time"
 		echo "	off: Turns off the cron job"
                  ;;

@@ Line 53: / Line 53: @@
 					opid=`cat .swapoff`
 					if [ `ps ax | grep $opid | grep swapclean` -eq "" ]
 						plog "PID not active or not owned by swapclean, clearing pid file"
 						rm -f .swapoff

@@ Line 8: / Line 8: @@
 #Watches swap usage
 #If there is swapping going on and there is enough free (+cache) ram, then turn swap off and back on.
 #User Assigned Variables
-swapthresh=0	#Swap threshold for clearing swap. Will not clear until this value is hit
+swapthresh=0	#Swap threshold for clearing swap. Will not clear until this value is hit. Good for servers that normally allocates small amounts of swap for some reason.
-freethresh=0	#Real free (free+cached) - current swap threshold. Ensures that atleast x bytes are free before clearing
+freethresh=0	#Real free (free+cached) - current swap threshold. Ensures that atleast x bytes are free before clearing.
 loadthresh=0	#Load threshold, will not clear if above this value (unless 0)
 logrotate=1000	#Max number of lines in the log file
@@ Line 23: / Line 25: @@
 		sed -i -e "1d" /var/log/swapclean
 	fi
+}
@@ Line 45: / Line 48: @@
 				if [ ! -e ".swapoff" ]
 				then
-					plog "Clearing swap"
+					clearswap
-					#Not currently clearing swap, nuke it.
+				else
 					plog "Lock file found, swap may be already clearing"
 				fi
 			else
@@ Line 61: / Line 67: @@
 		fi
 	fi
+	return
+}
 function enablecron {
+	if [ -e "/etc/cron.d/swapclean.sh" ]
 	then
-		crontime="*/10 * * * *"
+		echo "Cron already enabled, use change to set new time"
 	fi
-	echo "SHELL=/bin/bash" > /etc/cron.d/swapclean.sh
+	return
+}
 function disablecron {
+	if [ -e "/etc/cron.d/swapclean.sh" ]
-	rm -f /etc/cron.d/swapclean.sh
+	then
-	echo "Cron disabled"
+		rm -f /etc/cron.d/swapclean.sh
+		echo "Cron disabled"
+}
@@ Line 95: / Line 122: @@
 			off)
 				disablecron
 				;;
 		esac
@@ Line 100: / Line 131: @@
          --help)
                  echo "Check swap usage:"
-		echo " --cron [on, off]"
+		echo " --cron [on, change, off]"
 		echo "	on: Turns on cron job and asks for time"
 		echo "	off: Turns off the cron job"
                  ;;

@@ Line 119: / Line 119: @@
 ===loadthresh===
 This is the load level threshold at which the script will allow swap to be cleaned.
 ===logrotate===
 This is the number of lines that will be stored in the log file. When reached the top line will be deleted.

@@ Line 4: / Line 4: @@
 ==Script==
 <code>[bash,n]
 #!/bin/bash
 #Swap Cleaner
 #Watches swap usage
 #If there is swapping going on and there is enough free (+cache) ram, then turn swap off and back on.
-−
 #User Assigned Variables
-−
 swapthresh=0	#Swap threshold for clearing swap. Will not clear until this value is hit
 freethresh=0	#Real free (free+cached) - current swap threshold. Ensures that atleast x bytes are free before clearing
@@ Line 17: / Line 16: @@
 logrotate=1000	#Max number of lines in the log file
 ####
-−
 function plog {
 	echo "[ `date` ][ $curswap; $curfree; $realload ] $1" >> /var/log/swapclean
@@ Line 25: / Line 24: @@
 	fi
+}
-−
 function checkswap {
-−
 	curswap=`free | fgrep "Swap:" | awk '{print $3}'`
 	curfree=`free | fgrep "buffers/cache:" | awk '{print $4}'`
@@ Line 34: / Line 33: @@
 	loadthresh=`echo "$loadthresh *100" | bc | sed 's/[.].*//'`
 	swapdif=`expr $curfree - $curswap`
-−
 	if [ "$swapthresh" -lt "$curswap" ]
 	then
@@ Line 62: / Line 61: @@
 		fi
 	fi
-−
+}
-−
 function enablecron {
-−
 	echo "What time would you like to set the cron to"
 	echo "[IE: */10 * * * * ]"
@@ Line 75: / Line 74: @@
 	fi
 	echo "SHELL=/bin/bash" > /etc/cron.d/swapclean.sh
-	echo "$crontime $(readlink -f $0)" >> /etc/cron.d/swapclean.sh
+	echo "$crontime root $(readlink -f $0)" >> /etc/cron.d/swapclean.sh
 	chmod 0644 /etc/cron.d/swapclean.sh
-	echo "Cron enabled [$crontime $(readlink -f $0)]"
+	echo "Cron enabled [$crontime root $(readlink -f $0)]"
+}
-−
 function disablecron {
-−
 	rm -f /etc/cron.d/swapclean.sh
 	echo "Cron disabled"
-−
+}
-−
-−
 case $1 in
          --cron)

@@ Line 30: / Line 30: @@
 	curswap=`free | fgrep "Swap:" | awk '{print $3}'`
 	curfree=`free | fgrep "buffers/cache:" | awk '{print $4}'`
-	realload=`top -b -n1 | fgrep "load average" | rev | awk '{print $3}' | rev | sed 's/[,]//'`
+	realload=`cat /proc/loadavg | awk '{print $1}'`
 	curload=`echo "$realload * 100" | bc | sed 's/[.].*//'`
 	loadthresh=`echo "$loadthresh *100" | bc | sed 's/[.].*//'`