mysql dump + free space check + remove oldest to free up space

mysql dump

#!/bin/sh

user=user
ftpuser=$user
pass=password
db=dbname
host=remote/local
BkUp_dir="/home/$ftpuser/dbdump/"

########################################

dater=`date +%y%m%d`
sp_dl=0
dl_flag=0

echo "$(date "+%Y/%m/%d %R:%S") Starting Mysql backup session for user \"$user\" database \"$db\" "

echo "$(date "+%Y/%m/%d %R:%S") Checking if back-up directory \"$BkUp_dir\" exists.."
if [ -d $BkUp_dir ]
then 
        echo "$(date "+%Y/%m/%d %R:%S") Directory \"$BkUp_dir\" exists!"
else 
        echo "$(date "+%Y/%m/%d %R:%S") Directory \"$BkUp_dir\" doesn't exist!"
        echo "$(date "+%Y/%m/%d %R:%S") Creating directory \"$BkUp_dir\""
        mkdir $BkUp_dir
        chmod 700 $BkUp_dir
fi

echo "$(date "+%Y/%m/%d %R:%S") Estimating database \"$db\" size.."
exp_db_size=`mysql -h $host -P 6603 -u $user -p$pass -D $db -e "show table status\G"| egrep "(Index|Data)_length" | awk 'BEGIN { rsum = 0 } { rsum += $2 } END { 
print rsum }'`
exp_db_size=`expr $exp_db_size / 1024`
echo "$(date "+%Y/%m/%d %R:%S") Expected DB size (below): $exp_db_size kB"

echo "$(date "+%Y/%m/%d %R:%S") Estimating space available for user \"$ftpuser\".."
sp_av=`quota $ftpuser | grep "/dev/" | awk {'print $3-$2'}`
echo "$(date "+%Y/%m/%d %R:%S") Space available: $sp_av kB"

sp_lf=`expr $sp_av - $exp_db_size`

if [ $sp_lf -gt 0 ]
then
        echo "$(date "+%Y/%m/%d %R:%S") Executing mysqldump command.."
        `mysqldump -h $host -P 6603 -u $user -p$pass $db > $BkUp_dir$dater.sql`
        echo "$(date "+%Y/%m/%d %R:%S") Compressing mysqldump file.."
        `tar -pczf $BkUp_dir$dater.sql.gz $BkUp_dir$dater.sql 2>/dev/null`
        `rm $BkUp_dir$dater.sql`
        echo "$(date "+%Y/%m/%d %R:%S") Done! Backup \"$dater.sql.gz\" completed!"
else 
        echo "$(date "+%Y/%m/%d %R:%S") Theres not enough space available!"
        sql_list=`ls $BkUp_dir | grep "\.sql"`
        sql_count=`ls $BkUp_dir | grep "\.sql" | wc -l`
        if [ $sql_count -gt 0 ]
        then
                echo "$(date "+%Y/%m/%d %R:%S") There are $sql_count \".sql\" files!"
                for i in $sql_list
                        do 
                                bk_size=`du -s $BkUp_dir$i | awk {'print $1'}`
                                sp_dl=`expr $sp_dl + $bk_size`
                                if [ $sp_dl -ge $exp_db_size ] 
                                then 
                                        echo "$(date "+%Y/%m/%d %R:%S") $i $bk_size kB (If all DB's till this one are deleted: $sp_dl kB - Space required: $exp_db_size kB)"
                                        dl_flag=1
                                        break
                                fi
                        done
                if [ $dl_flag -eq 1 ]
                then
                        for j in $sql_list
                                do 
                                        echo "$(date "+%Y/%m/%d %R:%S") Deleting $j"
                                        #echo "rm $BkUp_dir$j"
                                        if [ "$j" = "$i" ]  
                                        then 
                                                echo "$(date "+%Y/%m/%d %R:%S") Executing mysqldump command.."
                                                `mysqldump -h $host -P 6603 -u $user -p$pass $db > $BkUp_dir$dater.sql`
                                                echo "$(date "+%Y/%m/%d %R:%S") Compressing mysqldump file.."
                                                `tar -pczf $BkUp_dir$dater.sql.gz $BkUp_dir$dater.sql 2>/dev/null`
                                                `rm $BkUp_dir$dater.sql`
                                                echo "$(date "+%Y/%m/%d %R:%S") Done! Backup \"$dater.sql.gz\" completed!"
                                                break 
                                        fi
                                done
else
                        echo "$(date "+%Y/%m/%d %R:%S") Even deleting all the back-up's won't free up enough space!"    
                        echo "$(date "+%Y/%m/%d %R:%S") Failed to make a Mysql back-up - Need more free space! Space available: $sp_av kB Space needed: $exp_db_size kB"
                fi
        else
        echo "$(date "+%Y/%m/%d %R:%S") There are no backups to delete to free up some space!"
                echo "$(date "+%Y/%m/%d %R:%S") Failed to make a Mysql back-up - Need more free space! Space available: $sp_av kB Space needed: $exp_db_size kB"
        fi
fi