03:01にディスクアクセスが発生。ずらしたい
# Perform daily/weekly/monthly maintenance. 1 3 * * * root periodic daily
と設定されていますので、毎日午前 3 時に /etc/periodic/daily ディレク
トリ以下の実行ファイルが実行されます(FreeBSD 4.2-RELEASE以前は午前 2 時)。
それによって行なわれる処理の為、ディスクアクセスが発生します。そのうちの
http://www.jp.freebsd.org/QandA/HTML/582.html
The periodic daily and periodic weekly jobs in /etc/crontab run find(1) for a couple of things. Part of the daily job is /etc/periodic/security/100.chksetuid and /etc/periodic/security/110.neggrpperm. One or both of those is fairly disk intensive. The weekly job rebuilds the locate(1) database, trying to catalog every file.
Might be easiest to set the daily and weekly execution times ten or twenty minutes later for each VM. Depending on the VMs, some of those jobs might be unnecessary and could be disabled in periodic.conf(5).
https://forums.freebsd.org/threads/47353/
/etc/anacrontab # the maximal random delay added to the base delay of the jobs RANDOM_DELAY=45
anacron の RANDOM_DELAY みたいなことをやりたい
シェルスクリプト ランダム値を得る
What if you add sleep $[ ( $RANDOM % 60 ) + 1 ]s? This way, you sleep a random number of seconds and after that perform the command:
* * * * * sleep $[ ( $RANDOM % 10 ) + 1 ]s && wget http://link.phpcpanel - How to give a random delay on Cron Jobs commands - Stack Overflow
1) On BSD systems, you can use jot(1):
sleep `jot -r 1 1 900`
2700(秒)=45分
# Perform daily/weekly/monthly maintenance. 1 3 * * * root sleep `jot -r 1 0 2700`; periodic daily
