設定した時間ごとにauth.logファイルをローテーションするcronjobがあることは知っていますが、実際のauth.logと比べてauth.log.1が小さいことに気付きました。 auth.logはauth.log.1に名前変更され、新しいauth.logは作成されませんか?
はいといいえ:
auth.log
はauth.log.1
に名前が変更されますauth.log.1
はauth.log
よりも小さいとは限りません。これは マシンの使用 に依存するためです。E.G .:私のマシンで:
ll /var/log/auth*
-rw-r----- 1 syslog adm 209K Nov 30 17:55 /var/log/auth.log
-rw-r----- 1 syslog adm 304K Nov 25 17:08 /var/log/auth.log.1
-rw-r----- 1 syslog adm 27K Nov 18 09:20 /var/log/auth.log.2.gz
-rw-r----- 1 syslog adm 16K Nov 11 07:35 /var/log/auth.log.3.gz
-rw-r----- 1 syslog adm 19K Nov 5 07:35 /var/log/auth.log.4.gz
ただし、他の(古い)ログは圧縮されるため、実際には小さくなります。
ログローテーションは、タスク用に設計されたlogrotate
パッケージによって管理されます。 man logrotate
から
NAME
logrotate ‐ rotates, compresses, and mails system logs
SYNOPSIS
logrotate [-dv] [-f|--force] [-s|--state file] config_file ..
DESCRIPTION
logrotate is designed to ease administration of systems that generate large numbers of log files. It allows automatic rotation, compression, removal, and mailing of
log files. Each log file may be handled daily, weekly, monthly, or when it grows too large.
Normally, logrotate is run as a daily cron job. It will not modify a log more than once in one day unless the criterion for that log is based on the log's size and
logrotate is being run more than once each day, or unless the -f or --force option is used.
Any number of config files may be given on the command line. Later config files may override the options given in earlier files, so the order in which the logrotate
config files are listed is important. Normally, a single config file which includes any other config files which are needed should be used. See below for more infor‐
mation on how to use the include directive to accomplish this. If a directory is given on the command line, every file in that directory is used as a config file.
If no command line arguments are given, logrotate will print version and copyright information, along with a short usage summary. If any errors occur while rotating
logs, logrotate will exit with non-zero status.