直接执行shell正常,crontab下运行报错?

suchasplus

vim mon.sh

#!/bin/bash blocksize=`blockdev --getbsz /dev/sdb1` output=getDiskIO.sh read_sum=0 read_count=0 for loop in `vmstat 1 6 | sed -n '4,8p' | awk '{print $9}'` do         read_sum=`expr $read_sum + $loop`         read_count=`expr $read_count + 1` done reader=`expr $read_sum / $read_count` bitrate=`expr $blocksize \* $reader` echo '#!/bin/bash' > $output echo "bitrate=$bitrate" >> $output echo 'echo $(awk "BEGIN{print $bitrate / 1048576 }")' >> $output

直接运行正常
但是放在crontab就说找不到blockdev  expr: syntax error
crontab -e

*/2 * * * * /root/plus/mon.sh

nbrr

把blockdev换成/sbin/blockdev

nuclearxin

#!/bin/sh
下加上 路径
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin